drivers/input/mouse/elantech.c

   1 /*
   2  * Elantech Touchpad driver (v6)
   3  *
   4  * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation.
   9  *
  10  * Trademarks are the property of their respective owners.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
  14
  15 #include <linux/delay.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/input.h>
  19 #include <linux/serio.h>
  20 #include <linux/libps2.h>
  21 #include "psmouse.h"
  22 #include "elantech.h"
  23
  24 #define elantech_debug(fmt, ...)                                        \
  25         do {                                                            \
  26                 if (etd->debug)                                         \
  27                         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);  \
  28         } while (0)
  29
  30 static bool force_elantech;
  31 module_param_named(force_elantech, force_elantech, bool, 0644);
  32 MODULE_PARM_DESC(force_elantech, "Force the Elantech PS/2 protocol extension to be used, 1 = enabled, 0 = disabled (default).");
  33
  34 /*
  35  * Send a Synaptics style sliced query command
  36  */
  37 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
  38                                 unsigned char *param)
  39 {
  40         if (psmouse_sliced_command(psmouse, c) ||
  41             ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
  42                 pr_err("synaptics_send_cmd query 0x%02x failed.\n", c);
  43                 return -1;
  44         }
  45
  46         return 0;
  47 }
  48
  49 /*
  50  * A retrying version of ps2_command
  51  */
  52 static int elantech_ps2_command(struct psmouse *psmouse,
  53                                 unsigned char *param, int command)
  54 {
  55         struct ps2dev *ps2dev = &psmouse->ps2dev;
  56         struct elantech_data *etd = psmouse->private;
  57         int rc;
  58         int tries = ETP_PS2_COMMAND_TRIES;
  59
  60         do {
  61                 rc = ps2_command(ps2dev, param, command);
  62                 if (rc == 0)
  63                         break;
  64                 tries--;
  65                 elantech_debug("retrying ps2 command 0x%02x (%d).\n",
  66                                 command, tries);
  67                 msleep(ETP_PS2_COMMAND_DELAY);
  68         } while (tries > 0);
  69
  70         if (rc)
  71                 pr_err("ps2 command 0x%02x failed.\n", command);
  72
  73         return rc;
  74 }
  75
  76 /*
  77  * Send an Elantech style special command to read a value from a register
  78  */
  79 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
  80                                 unsigned char *val)
  81 {
  82         struct elantech_data *etd = psmouse->private;
  83         unsigned char param[3];
  84         int rc = 0;
  85
  86         if (reg < 0x10 || reg > 0x26)
  87                 return -1;
  88
  89         if (reg > 0x11 && reg < 0x20)
  90                 return -1;
  91
  92         switch (etd->hw_version) {
  93         case 1:
  94                 if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
  95                     psmouse_sliced_command(psmouse, reg) ||
  96                     ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
  97                         rc = -1;
  98                 }
  99                 break;
 100
 101         case 2:
 102                 if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
 103                     elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
 104                     elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
 105                     elantech_ps2_command(psmouse,  NULL, reg) ||
 106                     elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
 107                         rc = -1;
 108                 }
 109                 break;
 110         }
 111
 112         if (rc)
 113                 pr_err("failed to read register 0x%02x.\n", reg);
 114         else
 115                 *val = param[0];
 116
 117         return rc;
 118 }
 119
 120 /*
 121  * Send an Elantech style special command to write a register with a value
 122  */
 123 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
 124                                 unsigned char val)
 125 {
 126         struct elantech_data *etd = psmouse->private;
 127         int rc = 0;
 128
 129         if (reg < 0x10 || reg > 0x26)
 130                 return -1;
 131
 132         if (reg > 0x11 && reg < 0x20)
 133                 return -1;
 134
 135         switch (etd->hw_version) {
 136         case 1:
 137                 if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
 138                     psmouse_sliced_command(psmouse, reg) ||
 139                     psmouse_sliced_command(psmouse, val) ||
 140                     ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
 141                         rc = -1;
 142                 }
 143                 break;
 144
 145         case 2:
 146                 if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 147                     elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
 148                     elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 149                     elantech_ps2_command(psmouse, NULL, reg) ||
 150                     elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 151                     elantech_ps2_command(psmouse, NULL, val) ||
 152                     elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
 153                         rc = -1;
 154                 }
 155                 break;
 156         }
 157
 158         if (rc)
 159                 pr_err("failed to write register 0x%02x with value 0x%02x.\n",
 160                         reg, val);
 161
 162         return rc;
 163 }
 164
 165 /*
 166  * Dump a complete mouse movement packet to the syslog
 167  */
 168 static void elantech_packet_dump(unsigned char *packet, int size)
 169 {
 170         int     i;
 171
 172         printk(KERN_DEBUG pr_fmt("PS/2 packet ["));
 173         for (i = 0; i < size; i++)
 174                 printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
 175         printk("]\n");
 176 }
 177
 178 /*
 179  * Interpret complete data packets and report absolute mode input events for
 180  * hardware version 1. (4 byte packets)
 181  */
 182 static void elantech_report_absolute_v1(struct psmouse *psmouse)
 183 {
 184         struct input_dev *dev = psmouse->dev;
 185         struct elantech_data *etd = psmouse->private;
 186         unsigned char *packet = psmouse->packet;
 187         int fingers;
 188
 189         if (etd->fw_version < 0x020000) {
 190                 /*
 191                  * byte 0:  D   U  p1  p2   1  p3   R   L
 192                  * byte 1:  f   0  th  tw  x9  x8  y9  y8
 193                  */
 194                 fingers = ((packet[1] & 0x80) >> 7) +
 195                                 ((packet[1] & 0x30) >> 4);
 196         } else {
 197                 /*
 198                  * byte 0: n1  n0  p2  p1   1  p3   R   L
 199                  * byte 1:  0   0   0   0  x9  x8  y9  y8
 200                  */
 201                 fingers = (packet[0] & 0xc0) >> 6;
 202         }
 203
 204         if (etd->jumpy_cursor) {
 205                 if (fingers != 1) {
 206                         etd->single_finger_reports = 0;
 207                 } else if (etd->single_finger_reports < 2) {
 208                         /* Discard first 2 reports of one finger, bogus */
 209                         etd->single_finger_reports++;
 210                         elantech_debug("discarding packet\n");
 211                         return;
 212                 }
 213         }
 214
 215         input_report_key(dev, BTN_TOUCH, fingers != 0);
 216
 217         /*
 218          * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
 219          * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
 220          */
 221         if (fingers) {
 222                 input_report_abs(dev, ABS_X,
 223                         ((packet[1] & 0x0c) << 6) | packet[2]);
 224                 input_report_abs(dev, ABS_Y,
 225                         ETP_YMAX_V1 - (((packet[1] & 0x03) << 8) | packet[3]));
 226         }
 227
 228         input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
 229         input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
 230         input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
 231         input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
 232         input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
 233
 234         if (etd->fw_version < 0x020000 &&
 235             (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
 236                 /* rocker up */
 237                 input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
 238                 /* rocker down */
 239                 input_report_key(dev, BTN_BACK, packet[0] & 0x80);
 240         }
 241
 242         input_sync(dev);
 243 }
 244
 245 /*
 246  * Interpret complete data packets and report absolute mode input events for
 247  * hardware version 2. (6 byte packets)
 248  */
 249 static void elantech_report_absolute_v2(struct psmouse *psmouse)
 250 {
 251         struct input_dev *dev = psmouse->dev;
 252         unsigned char *packet = psmouse->packet;
 253         int fingers, x1, y1, x2, y2;
 254
 255         /* byte 0: n1  n0   .   .   .   .   R   L */
 256         fingers = (packet[0] & 0xc0) >> 6;
 257         input_report_key(dev, BTN_TOUCH, fingers != 0);
 258
 259         switch (fingers) {
 260         case 3:
 261                 /*
 262                  * Same as one finger, except report of more than 3 fingers:
 263                  * byte 3:  n4  .   w1  w0   .   .   .   .
 264                  */
 265                 if (packet[3] & 0x80)
 266                         fingers = 4;
 267                 /* pass through... */
 268         case 1:
 269                 /*
 270                  * byte 1:  .   .   .   .   .  x10 x9  x8
 271                  * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
 272                  */
 273                 input_report_abs(dev, ABS_X,
 274                         ((packet[1] & 0x07) << 8) | packet[2]);
 275                 /*
 276                  * byte 4:  .   .   .   .   .   .  y9  y8
 277                  * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
 278                  */
 279                 input_report_abs(dev, ABS_Y,
 280                         ETP_YMAX_V2 - (((packet[4] & 0x03) << 8) | packet[5]));
 281                 break;
 282
 283         case 2:
 284                 /*
 285                  * The coordinate of each finger is reported separately
 286                  * with a lower resolution for two finger touches:
 287                  * byte 0:  .   .  ay8 ax8  .   .   .   .
 288                  * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
 289                  */
 290                 x1 = ((packet[0] & 0x10) << 4) | packet[1];
 291                 /* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
 292                 y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) | packet[2]);
 293                 /*
 294                  * byte 3:  .   .  by8 bx8  .   .   .   .
 295                  * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
 296                  */
 297                 x2 = ((packet[3] & 0x10) << 4) | packet[4];
 298                 /* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
 299                 y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) | packet[5]);
 300                 /*
 301                  * For compatibility with the X Synaptics driver scale up
 302                  * one coordinate and report as ordinary mouse movent
 303                  */
 304                 input_report_abs(dev, ABS_X, x1 << 2);
 305                 input_report_abs(dev, ABS_Y, y1 << 2);
 306                 /*
 307                  * For compatibility with the proprietary X Elantech driver
 308                  * report both coordinates as hat coordinates
 309                  */
 310                 input_report_abs(dev, ABS_HAT0X, x1);
 311                 input_report_abs(dev, ABS_HAT0Y, y1);
 312                 input_report_abs(dev, ABS_HAT1X, x2);
 313                 input_report_abs(dev, ABS_HAT1Y, y2);
 314                 break;
 315         }
 316
 317         input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
 318         input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
 319         input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
 320         input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
 321         input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
 322         input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
 323
 324         input_sync(dev);
 325 }
 326
 327 static int elantech_check_parity_v1(struct psmouse *psmouse)
 328 {
 329         struct elantech_data *etd = psmouse->private;
 330         unsigned char *packet = psmouse->packet;
 331         unsigned char p1, p2, p3;
 332
 333         /* Parity bits are placed differently */
 334         if (etd->fw_version < 0x020000) {
 335                 /* byte 0:  D   U  p1  p2   1  p3   R   L */
 336                 p1 = (packet[0] & 0x20) >> 5;
 337                 p2 = (packet[0] & 0x10) >> 4;
 338         } else {
 339                 /* byte 0: n1  n0  p2  p1   1  p3   R   L */
 340                 p1 = (packet[0] & 0x10) >> 4;
 341                 p2 = (packet[0] & 0x20) >> 5;
 342         }
 343
 344         p3 = (packet[0] & 0x04) >> 2;
 345
 346         return etd->parity[packet[1]] == p1 &&
 347                etd->parity[packet[2]] == p2 &&
 348                etd->parity[packet[3]] == p3;
 349 }
 350
 351 /*
 352  * Process byte stream from mouse and handle complete packets
 353  */
 354 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 355 {
 356         struct elantech_data *etd = psmouse->private;
 357
 358         if (psmouse->pktcnt < psmouse->pktsize)
 359                 return PSMOUSE_GOOD_DATA;
 360
 361         if (etd->debug > 1)
 362                 elantech_packet_dump(psmouse->packet, psmouse->pktsize);
 363
 364         switch (etd->hw_version) {
 365         case 1:
 366                 if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
 367                         return PSMOUSE_BAD_DATA;
 368
 369                 elantech_report_absolute_v1(psmouse);
 370                 break;
 371
 372         case 2:
 373                 /* We don't know how to check parity in protocol v2 */
 374                 elantech_report_absolute_v2(psmouse);
 375                 break;
 376         }
 377
 378         return PSMOUSE_FULL_PACKET;
 379 }
 380
 381 /*
 382  * Put the touchpad into absolute mode
 383  */
 384 static int elantech_set_absolute_mode(struct psmouse *psmouse)
 385 {
 386         struct elantech_data *etd = psmouse->private;
 387         unsigned char val;
 388         int tries = ETP_READ_BACK_TRIES;
 389         int rc = 0;
 390
 391         switch (etd->hw_version) {
 392         case 1:
 393                 etd->reg_10 = 0x16;
 394                 etd->reg_11 = 0x8f;
 395                 if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 396                     elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
 397                         rc = -1;
 398                 }
 399                 break;
 400
 401         case 2:
 402                                         /* Windows driver values */
 403                 etd->reg_10 = 0x54;
 404                 etd->reg_11 = 0x88;     /* 0x8a */
 405                 etd->reg_21 = 0x60;     /* 0x00 */
 406                 if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 407                     elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
 408                     elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
 409                         rc = -1;
 410                         break;
 411                 }
 412         }
 413
 414         if (rc == 0) {
 415                 /*
 416                  * Read back reg 0x10. For hardware version 1 we must make
 417                  * sure the absolute mode bit is set. For hardware version 2
 418                  * the touchpad is probably initalising and not ready until
 419                  * we read back the value we just wrote.
 420                  */
 421                 do {
 422                         rc = elantech_read_reg(psmouse, 0x10, &val);
 423                         if (rc == 0)
 424                                 break;
 425                         tries--;
 426                         elantech_debug("retrying read (%d).\n", tries);
 427                         msleep(ETP_READ_BACK_DELAY);
 428                 } while (tries > 0);
 429
 430                 if (rc) {
 431                         pr_err("failed to read back register 0x10.\n");
 432                 } else if (etd->hw_version == 1 &&
 433                            !(val & ETP_R10_ABSOLUTE_MODE)) {
 434                         pr_err("touchpad refuses to switch to absolute mode.\n");
 435                         rc = -1;
 436                 }
 437         }
 438
 439         if (rc)
 440                 pr_err("failed to initialise registers.\n");
 441
 442         return rc;
 443 }
 444
 445 /*
 446  * Set the appropriate event bits for the input subsystem
 447  */
 448 static void elantech_set_input_params(struct psmouse *psmouse)
 449 {
 450         struct input_dev *dev = psmouse->dev;
 451         struct elantech_data *etd = psmouse->private;
 452
 453         __set_bit(EV_KEY, dev->evbit);
 454         __set_bit(EV_ABS, dev->evbit);
 455         __clear_bit(EV_REL, dev->evbit);
 456
 457         __set_bit(BTN_LEFT, dev->keybit);
 458         __set_bit(BTN_RIGHT, dev->keybit);
 459
 460         __set_bit(BTN_TOUCH, dev->keybit);
 461         __set_bit(BTN_TOOL_FINGER, dev->keybit);
 462         __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
 463         __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
 464
 465         switch (etd->hw_version) {
 466         case 1:
 467                 /* Rocker button */
 468                 if (etd->fw_version < 0x020000 &&
 469                     (etd->capabilities & ETP_CAP_HAS_ROCKER)) {
 470                         __set_bit(BTN_FORWARD, dev->keybit);
 471                         __set_bit(BTN_BACK, dev->keybit);
 472                 }
 473                 input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
 474                 input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
 475                 break;
 476
 477         case 2:
 478                 __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
 479                 input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
 480                 input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
 481                 input_set_abs_params(dev, ABS_HAT0X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
 482                 input_set_abs_params(dev, ABS_HAT0Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
 483                 input_set_abs_params(dev, ABS_HAT1X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
 484                 input_set_abs_params(dev, ABS_HAT1Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
 485                 break;
 486         }
 487 }
 488
 489 struct elantech_attr_data {
 490         size_t          field_offset;
 491         unsigned char   reg;
 492 };
 493
 494 /*
 495  * Display a register value by reading a sysfs entry
 496  */
 497 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
 498                                         char *buf)
 499 {
 500         struct elantech_data *etd = psmouse->private;
 501         struct elantech_attr_data *attr = data;
 502         unsigned char *reg = (unsigned char *) etd + attr->field_offset;
 503         int rc = 0;
 504
 505         if (attr->reg)
 506                 rc = elantech_read_reg(psmouse, attr->reg, reg);
 507
 508         return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
 509 }
 510
 511 /*
 512  * Write a register value by writing a sysfs entry
 513  */
 514 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
 515                                      void *data, const char *buf, size_t count)
 516 {
 517         struct elantech_data *etd = psmouse->private;
 518         struct elantech_attr_data *attr = data;
 519         unsigned char *reg = (unsigned char *) etd + attr->field_offset;
 520         unsigned long value;
 521         int err;
 522
 523         err = strict_strtoul(buf, 16, &value);
 524         if (err)
 525                 return err;
 526
 527         if (value > 0xff)
 528                 return -EINVAL;
 529
 530         /* Do we need to preserve some bits for version 2 hardware too? */
 531         if (etd->hw_version == 1) {
 532                 if (attr->reg == 0x10)
 533                         /* Force absolute mode always on */
 534                         value |= ETP_R10_ABSOLUTE_MODE;
 535                 else if (attr->reg == 0x11)
 536                         /* Force 4 byte mode always on */
 537                         value |= ETP_R11_4_BYTE_MODE;
 538         }
 539
 540         if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
 541                 *reg = value;
 542
 543         return count;
 544 }
 545
 546 #define ELANTECH_INT_ATTR(_name, _register)                             \
 547         static struct elantech_attr_data elantech_attr_##_name = {      \
 548                 .field_offset = offsetof(struct elantech_data, _name),  \
 549                 .reg = _register,                                       \
 550         };                                                              \
 551         PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                   \
 552                             &elantech_attr_##_name,                     \
 553                             elantech_show_int_attr,                     \
 554                             elantech_set_int_attr)
 555
 556 ELANTECH_INT_ATTR(reg_10, 0x10);
 557 ELANTECH_INT_ATTR(reg_11, 0x11);
 558 ELANTECH_INT_ATTR(reg_20, 0x20);
 559 ELANTECH_INT_ATTR(reg_21, 0x21);
 560 ELANTECH_INT_ATTR(reg_22, 0x22);
 561 ELANTECH_INT_ATTR(reg_23, 0x23);
 562 ELANTECH_INT_ATTR(reg_24, 0x24);
 563 ELANTECH_INT_ATTR(reg_25, 0x25);
 564 ELANTECH_INT_ATTR(reg_26, 0x26);
 565 ELANTECH_INT_ATTR(debug, 0);
 566 ELANTECH_INT_ATTR(paritycheck, 0);
 567
 568 static struct attribute *elantech_attrs[] = {
 569         &psmouse_attr_reg_10.dattr.attr,
 570         &psmouse_attr_reg_11.dattr.attr,
 571         &psmouse_attr_reg_20.dattr.attr,
 572         &psmouse_attr_reg_21.dattr.attr,
 573         &psmouse_attr_reg_22.dattr.attr,
 574         &psmouse_attr_reg_23.dattr.attr,
 575         &psmouse_attr_reg_24.dattr.attr,
 576         &psmouse_attr_reg_25.dattr.attr,
 577         &psmouse_attr_reg_26.dattr.attr,
 578         &psmouse_attr_debug.dattr.attr,
 579         &psmouse_attr_paritycheck.dattr.attr,
 580         NULL
 581 };
 582
 583 static struct attribute_group elantech_attr_group = {
 584         .attrs = elantech_attrs,
 585 };
 586
 587 static bool elantech_is_signature_valid(const unsigned char *param)
 588 {
 589         static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
 590         int i;
 591
 592         if (param[0] == 0)
 593                 return false;
 594
 595         if (param[1] == 0)
 596                 return true;
 597
 598         for (i = 0; i < ARRAY_SIZE(rates); i++)
 599                 if (param[2] == rates[i])
 600                         return false;
 601
 602         return true;
 603 }
 604
 605 /*
 606  * Use magic knock to detect Elantech touchpad
 607  */
 608 int elantech_detect(struct psmouse *psmouse, bool set_properties)
 609 {
 610         struct ps2dev *ps2dev = &psmouse->ps2dev;
 611         unsigned char param[3];
 612
 613         ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
 614
 615         if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
 616             ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
 617             ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
 618             ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
 619             ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
 620                 pr_debug("sending Elantech magic knock failed.\n");
 621                 return -1;
 622         }
 623
 624         /*
 625          * Report this in case there are Elantech models that use a different
 626          * set of magic numbers
 627          */
 628         if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
 629                 pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
 630                          param[0], param[1], param[2]);
 631                 return -1;
 632         }
 633
 634         /*
 635          * Query touchpad's firmware version and see if it reports known
 636          * value to avoid mis-detection. Logitech mice are known to respond
 637          * to Elantech magic knock and there might be more.
 638          */
 639         if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
 640                 pr_debug("failed to query firmware version.\n");
 641                 return -1;
 642         }
 643
 644         pr_debug("Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
 645                  param[0], param[1], param[2]);
 646
 647         if (!elantech_is_signature_valid(param)) {
 648                 if (!force_elantech) {
 649                         pr_debug("Probably not a real Elantech touchpad. Aborting.\n");
 650                         return -1;
 651                 }
 652
 653                 pr_debug("Probably not a real Elantech touchpad. Enabling anyway due to force_elantech.\n");
 654         }
 655
 656         if (set_properties) {
 657                 psmouse->vendor = "Elantech";
 658                 psmouse->name = "Touchpad";
 659         }
 660
 661         return 0;
 662 }
 663
 664 /*
 665  * Clean up sysfs entries when disconnecting
 666  */
 667 static void elantech_disconnect(struct psmouse *psmouse)
 668 {
 669         sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
 670                            &elantech_attr_group);
 671         kfree(psmouse->private);
 672         psmouse->private = NULL;
 673 }
 674
 675 /*
 676  * Put the touchpad back into absolute mode when reconnecting
 677  */
 678 static int elantech_reconnect(struct psmouse *psmouse)
 679 {
 680         if (elantech_detect(psmouse, 0))
 681                 return -1;
 682
 683         if (elantech_set_absolute_mode(psmouse)) {
 684                 pr_err("failed to put touchpad back into absolute mode.\n");
 685                 return -1;
 686         }
 687
 688         return 0;
 689 }
 690
 691 /*
 692  * Initialize the touchpad and create sysfs entries
 693  */
 694 int elantech_init(struct psmouse *psmouse)
 695 {
 696         struct elantech_data *etd;
 697         int i, error;
 698         unsigned char param[3];
 699
 700         psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
 701         if (!etd)
 702                 return -ENOMEM;
 703
 704         etd->parity[0] = 1;
 705         for (i = 1; i < 256; i++)
 706                 etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
 707
 708         /*
 709          * Do the version query again so we can store the result
 710          */
 711         if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
 712                 pr_err("failed to query firmware version.\n");
 713                 goto init_fail;
 714         }
 715
 716         etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
 717
 718         /*
 719          * Assume every version greater than this is new EeePC style
 720          * hardware with 6 byte packets
 721          */
 722         if (etd->fw_version >= 0x020030) {
 723                 etd->hw_version = 2;
 724                 /* For now show extra debug information */
 725                 etd->debug = 1;
 726                 /* Don't know how to do parity checking for version 2 */
 727                 etd->paritycheck = 0;
 728         } else {
 729                 etd->hw_version = 1;
 730                 etd->paritycheck = 1;
 731         }
 732
 733         pr_info("assuming hardware version %d, firmware version %d.%d.%d\n",
 734                 etd->hw_version, param[0], param[1], param[2]);
 735
 736         if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
 737                 pr_err("failed to query capabilities.\n");
 738                 goto init_fail;
 739         }
 740         pr_info("Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
 741                 param[0], param[1], param[2]);
 742         etd->capabilities = param[0];
 743
 744         /*
 745          * This firmware suffers from misreporting coordinates when
 746          * a touch action starts causing the mouse cursor or scrolled page
 747          * to jump. Enable a workaround.
 748          */
 749         if (etd->fw_version == 0x020022 || etd->fw_version == 0x020600) {
 750                 pr_info("firmware version 2.0.34/2.6.0 detected, enabling jumpy cursor workaround\n");
 751                 etd->jumpy_cursor = true;
 752         }
 753
 754         if (elantech_set_absolute_mode(psmouse)) {
 755                 pr_err("failed to put touchpad into absolute mode.\n");
 756                 goto init_fail;
 757         }
 758
 759         elantech_set_input_params(psmouse);
 760
 761         error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
 762                                    &elantech_attr_group);
 763         if (error) {
 764                 pr_err("failed to create sysfs attributes, error: %d.\n", error);
 765                 goto init_fail;
 766         }
 767
 768         psmouse->protocol_handler = elantech_process_byte;
 769         psmouse->disconnect = elantech_disconnect;
 770         psmouse->reconnect = elantech_reconnect;
 771         psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
 772
 773         return 0;
 774
 775  init_fail:
 776         kfree(etd);
 777         return -1;
 778 }