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/input/mt.h>
  20 #include <linux/serio.h>
  21 #include <linux/libps2.h>
  22 #include "psmouse.h"
  23 #include "elantech.h"
  24
  25 #define elantech_debug(fmt, ...)                                        \
  26         do {                                                            \
  27                 if (etd->debug)                                         \
  28                         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);  \
  29         } while (0)
  30
  31 static bool force_elantech;
  32 module_param_named(force_elantech, force_elantech, bool, 0644);
  33 MODULE_PARM_DESC(force_elantech, "Force the Elantech PS/2 protocol extension to be used, 1 = enabled, 0 = disabled (default).");
  34
  35 /*
  36  * Send a Synaptics style sliced query command
  37  */
  38 static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
  39                                 unsigned char *param)
  40 {
  41         if (psmouse_sliced_command(psmouse, c) ||
  42             ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
  43                 pr_err("synaptics_send_cmd query 0x%02x failed.\n", c);
  44                 return -1;
  45         }
  46
  47         return 0;
  48 }
  49
  50 /*
  51  * A retrying version of ps2_command
  52  */
  53 static int elantech_ps2_command(struct psmouse *psmouse,
  54                                 unsigned char *param, int command)
  55 {
  56         struct ps2dev *ps2dev = &psmouse->ps2dev;
  57         struct elantech_data *etd = psmouse->private;
  58         int rc;
  59         int tries = ETP_PS2_COMMAND_TRIES;
  60
  61         do {
  62                 rc = ps2_command(ps2dev, param, command);
  63                 if (rc == 0)
  64                         break;
  65                 tries--;
  66                 elantech_debug("retrying ps2 command 0x%02x (%d).\n",
  67                                 command, tries);
  68                 msleep(ETP_PS2_COMMAND_DELAY);
  69         } while (tries > 0);
  70
  71         if (rc)
  72                 pr_err("ps2 command 0x%02x failed.\n", command);
  73
  74         return rc;
  75 }
  76
  77 /*
  78  * Send an Elantech style special command to read a value from a register
  79  */
  80 static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
  81                                 unsigned char *val)
  82 {
  83         struct elantech_data *etd = psmouse->private;
  84         unsigned char param[3];
  85         int rc = 0;
  86
  87         if (reg < 0x10 || reg > 0x26)
  88                 return -1;
  89
  90         if (reg > 0x11 && reg < 0x20)
  91                 return -1;
  92
  93         switch (etd->hw_version) {
  94         case 1:
  95                 if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
  96                     psmouse_sliced_command(psmouse, reg) ||
  97                     ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
  98                         rc = -1;
  99                 }
 100                 break;
 101
 102         case 2:
 103                 if (elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
 104                     elantech_ps2_command(psmouse,  NULL, ETP_REGISTER_READ) ||
 105                     elantech_ps2_command(psmouse,  NULL, ETP_PS2_CUSTOM_COMMAND) ||
 106                     elantech_ps2_command(psmouse,  NULL, reg) ||
 107                     elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
 108                         rc = -1;
 109                 }
 110                 break;
 111         }
 112
 113         if (rc)
 114                 pr_err("failed to read register 0x%02x.\n", reg);
 115         else
 116                 *val = param[0];
 117
 118         return rc;
 119 }
 120
 121 /*
 122  * Send an Elantech style special command to write a register with a value
 123  */
 124 static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
 125                                 unsigned char val)
 126 {
 127         struct elantech_data *etd = psmouse->private;
 128         int rc = 0;
 129
 130         if (reg < 0x10 || reg > 0x26)
 131                 return -1;
 132
 133         if (reg > 0x11 && reg < 0x20)
 134                 return -1;
 135
 136         switch (etd->hw_version) {
 137         case 1:
 138                 if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
 139                     psmouse_sliced_command(psmouse, reg) ||
 140                     psmouse_sliced_command(psmouse, val) ||
 141                     ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
 142                         rc = -1;
 143                 }
 144                 break;
 145
 146         case 2:
 147                 if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 148                     elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
 149                     elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 150                     elantech_ps2_command(psmouse, NULL, reg) ||
 151                     elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
 152                     elantech_ps2_command(psmouse, NULL, val) ||
 153                     elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
 154                         rc = -1;
 155                 }
 156                 break;
 157         }
 158
 159         if (rc)
 160                 pr_err("failed to write register 0x%02x with value 0x%02x.\n",
 161                         reg, val);
 162
 163         return rc;
 164 }
 165
 166 /*
 167  * Dump a complete mouse movement packet to the syslog
 168  */
 169 static void elantech_packet_dump(unsigned char *packet, int size)
 170 {
 171         int     i;
 172
 173         printk(KERN_DEBUG pr_fmt("PS/2 packet ["));
 174         for (i = 0; i < size; i++)
 175                 printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
 176         printk("]\n");
 177 }
 178
 179 /*
 180  * Interpret complete data packets and report absolute mode input events for
 181  * hardware version 1. (4 byte packets)
 182  */
 183 static void elantech_report_absolute_v1(struct psmouse *psmouse)
 184 {
 185         struct input_dev *dev = psmouse->dev;
 186         struct elantech_data *etd = psmouse->private;
 187         unsigned char *packet = psmouse->packet;
 188         int fingers;
 189
 190         if (etd->fw_version < 0x020000) {
 191                 /*
 192                  * byte 0:  D   U  p1  p2   1  p3   R   L
 193                  * byte 1:  f   0  th  tw  x9  x8  y9  y8
 194                  */
 195                 fingers = ((packet[1] & 0x80) >> 7) +
 196                                 ((packet[1] & 0x30) >> 4);
 197         } else {
 198                 /*
 199                  * byte 0: n1  n0  p2  p1   1  p3   R   L
 200                  * byte 1:  0   0   0   0  x9  x8  y9  y8
 201                  */
 202                 fingers = (packet[0] & 0xc0) >> 6;
 203         }
 204
 205         if (etd->jumpy_cursor) {
 206                 if (fingers != 1) {
 207                         etd->single_finger_reports = 0;
 208                 } else if (etd->single_finger_reports < 2) {
 209                         /* Discard first 2 reports of one finger, bogus */
 210                         etd->single_finger_reports++;
 211                         elantech_debug("discarding packet\n");
 212                         return;
 213                 }
 214         }
 215
 216         input_report_key(dev, BTN_TOUCH, fingers != 0);
 217
 218         /*
 219          * byte 2: x7  x6  x5  x4  x3  x2  x1  x0
 220          * byte 3: y7  y6  y5  y4  y3  y2  y1  y0
 221          */
 222         if (fingers) {
 223                 input_report_abs(dev, ABS_X,
 224                         ((packet[1] & 0x0c) << 6) | packet[2]);
 225                 input_report_abs(dev, ABS_Y,
 226                         etd->y_max - (((packet[1] & 0x03) << 8) | packet[3]));
 227         }
 228
 229         input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
 230         input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
 231         input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
 232         input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
 233         input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
 234
 235         if (etd->fw_version < 0x020000 &&
 236             (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
 237                 /* rocker up */
 238                 input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
 239                 /* rocker down */
 240                 input_report_key(dev, BTN_BACK, packet[0] & 0x80);
 241         }
 242
 243         input_sync(dev);
 244 }
 245
 246 static void elantech_set_slot(struct input_dev *dev, int slot, bool active,
 247                               unsigned int x, unsigned int y)
 248 {
 249         input_mt_slot(dev, slot);
 250         input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
 251         if (active) {
 252                 input_report_abs(dev, ABS_MT_POSITION_X, x);
 253                 input_report_abs(dev, ABS_MT_POSITION_Y, y);
 254         }
 255 }
 256
 257 /* x1 < x2 and y1 < y2 when two fingers, x = y = 0 when not pressed */
 258 static void elantech_report_semi_mt_data(struct input_dev *dev,
 259                                          unsigned int num_fingers,
 260                                          unsigned int x1, unsigned int y1,
 261                                          unsigned int x2, unsigned int y2)
 262 {
 263         elantech_set_slot(dev, 0, num_fingers != 0, x1, y1);
 264         elantech_set_slot(dev, 1, num_fingers == 2, x2, y2);
 265 }
 266
 267 /*
 268  * Interpret complete data packets and report absolute mode input events for
 269  * hardware version 2. (6 byte packets)
 270  */
 271 static void elantech_report_absolute_v2(struct psmouse *psmouse)
 272 {
 273         struct elantech_data *etd = psmouse->private;
 274         struct input_dev *dev = psmouse->dev;
 275         unsigned char *packet = psmouse->packet;
 276         unsigned int fingers, x1 = 0, y1 = 0, x2 = 0, y2 = 0;
 277         unsigned int width = 0, pres = 0;
 278
 279         /* byte 0: n1  n0   .   .   .   .   R   L */
 280         fingers = (packet[0] & 0xc0) >> 6;
 281
 282         switch (fingers) {
 283         case 3:
 284                 /*
 285                  * Same as one finger, except report of more than 3 fingers:
 286                  * byte 3:  n4  .   w1  w0   .   .   .   .
 287                  */
 288                 if (packet[3] & 0x80)
 289                         fingers = 4;
 290                 /* pass through... */
 291         case 1:
 292                 /*
 293                  * byte 1:  .   .   .   .  x11 x10 x9  x8
 294                  * byte 2: x7  x6  x5  x4  x4  x2  x1  x0
 295                  */
 296                 x1 = ((packet[1] & 0x0f) << 8) | packet[2];
 297                 /*
 298                  * byte 4:  .   .   .   .  y11 y10 y9  y8
 299                  * byte 5: y7  y6  y5  y4  y3  y2  y1  y0
 300                  */
 301                 y1 = etd->y_max - (((packet[4] & 0x0f) << 8) | packet[5]);
 302
 303                 pres = (packet[1] & 0xf0) | ((packet[4] & 0xf0) >> 4);
 304                 width = ((packet[0] & 0x30) >> 2) | ((packet[3] & 0x30) >> 4);
 305                 break;
 306
 307         case 2:
 308                 /*
 309                  * The coordinate of each finger is reported separately
 310                  * with a lower resolution for two finger touches:
 311                  * byte 0:  .   .  ay8 ax8  .   .   .   .
 312                  * byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
 313                  */
 314                 x1 = (((packet[0] & 0x10) << 4) | packet[1]) << 2;
 315                 /* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
 316                 y1 = etd->y_max -
 317                         ((((packet[0] & 0x20) << 3) | packet[2]) << 2);
 318                 /*
 319                  * byte 3:  .   .  by8 bx8  .   .   .   .
 320                  * byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
 321                  */
 322                 x2 = (((packet[3] & 0x10) << 4) | packet[4]) << 2;
 323                 /* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
 324                 y2 = etd->y_max -
 325                         ((((packet[3] & 0x20) << 3) | packet[5]) << 2);
 326
 327                 /* Unknown so just report sensible values */
 328                 pres = 127;
 329                 width = 7;
 330                 break;
 331         }
 332
 333         input_report_key(dev, BTN_TOUCH, fingers != 0);
 334         if (fingers != 0) {
 335                 input_report_abs(dev, ABS_X, x1);
 336                 input_report_abs(dev, ABS_Y, y1);
 337         }
 338         elantech_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
 339         input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
 340         input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
 341         input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
 342         input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
 343         input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
 344         input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
 345         if (etd->reports_pressure) {
 346                 input_report_abs(dev, ABS_PRESSURE, pres);
 347                 input_report_abs(dev, ABS_TOOL_WIDTH, width);
 348         }
 349
 350         input_sync(dev);
 351 }
 352
 353 static int elantech_check_parity_v1(struct psmouse *psmouse)
 354 {
 355         struct elantech_data *etd = psmouse->private;
 356         unsigned char *packet = psmouse->packet;
 357         unsigned char p1, p2, p3;
 358
 359         /* Parity bits are placed differently */
 360         if (etd->fw_version < 0x020000) {
 361                 /* byte 0:  D   U  p1  p2   1  p3   R   L */
 362                 p1 = (packet[0] & 0x20) >> 5;
 363                 p2 = (packet[0] & 0x10) >> 4;
 364         } else {
 365                 /* byte 0: n1  n0  p2  p1   1  p3   R   L */
 366                 p1 = (packet[0] & 0x10) >> 4;
 367                 p2 = (packet[0] & 0x20) >> 5;
 368         }
 369
 370         p3 = (packet[0] & 0x04) >> 2;
 371
 372         return etd->parity[packet[1]] == p1 &&
 373                etd->parity[packet[2]] == p2 &&
 374                etd->parity[packet[3]] == p3;
 375 }
 376
 377 /*
 378  * Process byte stream from mouse and handle complete packets
 379  */
 380 static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
 381 {
 382         struct elantech_data *etd = psmouse->private;
 383
 384         if (psmouse->pktcnt < psmouse->pktsize)
 385                 return PSMOUSE_GOOD_DATA;
 386
 387         if (etd->debug > 1)
 388                 elantech_packet_dump(psmouse->packet, psmouse->pktsize);
 389
 390         switch (etd->hw_version) {
 391         case 1:
 392                 if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
 393                         return PSMOUSE_BAD_DATA;
 394
 395                 elantech_report_absolute_v1(psmouse);
 396                 break;
 397
 398         case 2:
 399                 /* We don't know how to check parity in protocol v2 */
 400                 elantech_report_absolute_v2(psmouse);
 401                 break;
 402         }
 403
 404         return PSMOUSE_FULL_PACKET;
 405 }
 406
 407 /*
 408  * Put the touchpad into absolute mode
 409  */
 410 static int elantech_set_absolute_mode(struct psmouse *psmouse)
 411 {
 412         struct elantech_data *etd = psmouse->private;
 413         unsigned char val;
 414         int tries = ETP_READ_BACK_TRIES;
 415         int rc = 0;
 416
 417         switch (etd->hw_version) {
 418         case 1:
 419                 etd->reg_10 = 0x16;
 420                 etd->reg_11 = 0x8f;
 421                 if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 422                     elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
 423                         rc = -1;
 424                 }
 425                 break;
 426
 427         case 2:
 428                                         /* Windows driver values */
 429                 etd->reg_10 = 0x54;
 430                 etd->reg_11 = 0x88;     /* 0x8a */
 431                 etd->reg_21 = 0x60;     /* 0x00 */
 432                 if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
 433                     elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
 434                     elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
 435                         rc = -1;
 436                         break;
 437                 }
 438         }
 439
 440         if (rc == 0) {
 441                 /*
 442                  * Read back reg 0x10. For hardware version 1 we must make
 443                  * sure the absolute mode bit is set. For hardware version 2
 444                  * the touchpad is probably initalising and not ready until
 445                  * we read back the value we just wrote.
 446                  */
 447                 do {
 448                         rc = elantech_read_reg(psmouse, 0x10, &val);
 449                         if (rc == 0)
 450                                 break;
 451                         tries--;
 452                         elantech_debug("retrying read (%d).\n", tries);
 453                         msleep(ETP_READ_BACK_DELAY);
 454                 } while (tries > 0);
 455
 456                 if (rc) {
 457                         pr_err("failed to read back register 0x10.\n");
 458                 } else if (etd->hw_version == 1 &&
 459                            !(val & ETP_R10_ABSOLUTE_MODE)) {
 460                         pr_err("touchpad refuses to switch to absolute mode.\n");
 461                         rc = -1;
 462                 }
 463         }
 464
 465         if (rc)
 466                 pr_err("failed to initialise registers.\n");
 467
 468         return rc;
 469 }
 470
 471 static void elantech_set_range(struct psmouse *psmouse,
 472                                unsigned int *x_min, unsigned int *y_min,
 473                                unsigned int *x_max, unsigned int *y_max)
 474 {
 475         struct elantech_data *etd = psmouse->private;
 476         int i;
 477
 478         switch (etd->hw_version) {
 479         case 1:
 480                 *x_min = ETP_XMIN_V1;
 481                 *y_min = ETP_YMIN_V1;
 482                 *x_max = ETP_XMAX_V1;
 483                 *y_max = ETP_YMAX_V1;
 484                 break;
 485
 486         case 2:
 487                 if (etd->fw_version == 0x020800 ||
 488                     etd->fw_version == 0x020b00 ||
 489                     etd->fw_version == 0x020030) {
 490                         *x_min = ETP_XMIN_V2;
 491                         *y_min = ETP_YMIN_V2;
 492                         *x_max = ETP_XMAX_V2;
 493                         *y_max = ETP_YMAX_V2;
 494                 } else {
 495                         i = (etd->fw_version > 0x020800 &&
 496                              etd->fw_version < 0x020900) ? 1 : 2;
 497                         *x_min = 0;
 498                         *y_min = 0;
 499                         *x_max = (etd->capabilities[1] - i) * 64;
 500                         *y_max = (etd->capabilities[2] - i) * 64;
 501                 }
 502                 break;
 503         }
 504 }
 505
 506 /*
 507  * Set the appropriate event bits for the input subsystem
 508  */
 509 static void elantech_set_input_params(struct psmouse *psmouse)
 510 {
 511         struct input_dev *dev = psmouse->dev;
 512         struct elantech_data *etd = psmouse->private;
 513         unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0;
 514
 515         elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max);
 516
 517         __set_bit(EV_KEY, dev->evbit);
 518         __set_bit(EV_ABS, dev->evbit);
 519         __clear_bit(EV_REL, dev->evbit);
 520
 521         __set_bit(BTN_LEFT, dev->keybit);
 522         __set_bit(BTN_RIGHT, dev->keybit);
 523
 524         __set_bit(BTN_TOUCH, dev->keybit);
 525         __set_bit(BTN_TOOL_FINGER, dev->keybit);
 526         __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
 527         __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
 528
 529         switch (etd->hw_version) {
 530         case 1:
 531                 /* Rocker button */
 532                 if (etd->fw_version < 0x020000 &&
 533                     (etd->capabilities[0] & ETP_CAP_HAS_ROCKER)) {
 534                         __set_bit(BTN_FORWARD, dev->keybit);
 535                         __set_bit(BTN_BACK, dev->keybit);
 536                 }
 537                 input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
 538                 input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
 539                 break;
 540
 541         case 2:
 542                 __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
 543                 input_set_abs_params(dev, ABS_X, x_min, x_max, 0, 0);
 544                 input_set_abs_params(dev, ABS_Y, y_min, y_max, 0, 0);
 545                 if (etd->reports_pressure) {
 546                         input_set_abs_params(dev, ABS_PRESSURE, ETP_PMIN_V2,
 547                                              ETP_PMAX_V2, 0, 0);
 548                         input_set_abs_params(dev, ABS_TOOL_WIDTH, ETP_WMIN_V2,
 549                                              ETP_WMAX_V2, 0, 0);
 550                 }
 551                 __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
 552                 input_mt_init_slots(dev, 2);
 553                 input_set_abs_params(dev, ABS_MT_POSITION_X, x_min, x_max, 0, 0);
 554                 input_set_abs_params(dev, ABS_MT_POSITION_Y, y_min, y_max, 0, 0);
 555                 break;
 556         }
 557
 558         etd->y_max = y_max;
 559 }
 560
 561 struct elantech_attr_data {
 562         size_t          field_offset;
 563         unsigned char   reg;
 564 };
 565
 566 /*
 567  * Display a register value by reading a sysfs entry
 568  */
 569 static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
 570                                         char *buf)
 571 {
 572         struct elantech_data *etd = psmouse->private;
 573         struct elantech_attr_data *attr = data;
 574         unsigned char *reg = (unsigned char *) etd + attr->field_offset;
 575         int rc = 0;
 576
 577         if (attr->reg)
 578                 rc = elantech_read_reg(psmouse, attr->reg, reg);
 579
 580         return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
 581 }
 582
 583 /*
 584  * Write a register value by writing a sysfs entry
 585  */
 586 static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
 587                                      void *data, const char *buf, size_t count)
 588 {
 589         struct elantech_data *etd = psmouse->private;
 590         struct elantech_attr_data *attr = data;
 591         unsigned char *reg = (unsigned char *) etd + attr->field_offset;
 592         unsigned long value;
 593         int err;
 594
 595         err = strict_strtoul(buf, 16, &value);
 596         if (err)
 597                 return err;
 598
 599         if (value > 0xff)
 600                 return -EINVAL;
 601
 602         /* Do we need to preserve some bits for version 2 hardware too? */
 603         if (etd->hw_version == 1) {
 604                 if (attr->reg == 0x10)
 605                         /* Force absolute mode always on */
 606                         value |= ETP_R10_ABSOLUTE_MODE;
 607                 else if (attr->reg == 0x11)
 608                         /* Force 4 byte mode always on */
 609                         value |= ETP_R11_4_BYTE_MODE;
 610         }
 611
 612         if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
 613                 *reg = value;
 614
 615         return count;
 616 }
 617
 618 #define ELANTECH_INT_ATTR(_name, _register)                             \
 619         static struct elantech_attr_data elantech_attr_##_name = {      \
 620                 .field_offset = offsetof(struct elantech_data, _name),  \
 621                 .reg = _register,                                       \
 622         };                                                              \
 623         PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,                   \
 624                             &elantech_attr_##_name,                     \
 625                             elantech_show_int_attr,                     \
 626                             elantech_set_int_attr)
 627
 628 ELANTECH_INT_ATTR(reg_10, 0x10);
 629 ELANTECH_INT_ATTR(reg_11, 0x11);
 630 ELANTECH_INT_ATTR(reg_20, 0x20);
 631 ELANTECH_INT_ATTR(reg_21, 0x21);
 632 ELANTECH_INT_ATTR(reg_22, 0x22);
 633 ELANTECH_INT_ATTR(reg_23, 0x23);
 634 ELANTECH_INT_ATTR(reg_24, 0x24);
 635 ELANTECH_INT_ATTR(reg_25, 0x25);
 636 ELANTECH_INT_ATTR(reg_26, 0x26);
 637 ELANTECH_INT_ATTR(debug, 0);
 638 ELANTECH_INT_ATTR(paritycheck, 0);
 639
 640 static struct attribute *elantech_attrs[] = {
 641         &psmouse_attr_reg_10.dattr.attr,
 642         &psmouse_attr_reg_11.dattr.attr,
 643         &psmouse_attr_reg_20.dattr.attr,
 644         &psmouse_attr_reg_21.dattr.attr,
 645         &psmouse_attr_reg_22.dattr.attr,
 646         &psmouse_attr_reg_23.dattr.attr,
 647         &psmouse_attr_reg_24.dattr.attr,
 648         &psmouse_attr_reg_25.dattr.attr,
 649         &psmouse_attr_reg_26.dattr.attr,
 650         &psmouse_attr_debug.dattr.attr,
 651         &psmouse_attr_paritycheck.dattr.attr,
 652         NULL
 653 };
 654
 655 static struct attribute_group elantech_attr_group = {
 656         .attrs = elantech_attrs,
 657 };
 658
 659 static bool elantech_is_signature_valid(const unsigned char *param)
 660 {
 661         static const unsigned char rates[] = { 200, 100, 80, 60, 40, 20, 10 };
 662         int i;
 663
 664         if (param[0] == 0)
 665                 return false;
 666
 667         if (param[1] == 0)
 668                 return true;
 669
 670         for (i = 0; i < ARRAY_SIZE(rates); i++)
 671                 if (param[2] == rates[i])
 672                         return false;
 673
 674         return true;
 675 }
 676
 677 /*
 678  * Use magic knock to detect Elantech touchpad
 679  */
 680 int elantech_detect(struct psmouse *psmouse, bool set_properties)
 681 {
 682         struct ps2dev *ps2dev = &psmouse->ps2dev;
 683         unsigned char param[3];
 684
 685         ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
 686
 687         if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_DISABLE) ||
 688             ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
 689             ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
 690             ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE11) ||
 691             ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
 692                 pr_debug("sending Elantech magic knock failed.\n");
 693                 return -1;
 694         }
 695
 696         /*
 697          * Report this in case there are Elantech models that use a different
 698          * set of magic numbers
 699          */
 700         if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
 701                 pr_debug("unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
 702                          param[0], param[1], param[2]);
 703                 return -1;
 704         }
 705
 706         /*
 707          * Query touchpad's firmware version and see if it reports known
 708          * value to avoid mis-detection. Logitech mice are known to respond
 709          * to Elantech magic knock and there might be more.
 710          */
 711         if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
 712                 pr_debug("failed to query firmware version.\n");
 713                 return -1;
 714         }
 715
 716         pr_debug("Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
 717                  param[0], param[1], param[2]);
 718
 719         if (!elantech_is_signature_valid(param)) {
 720                 if (!force_elantech) {
 721                         pr_debug("Probably not a real Elantech touchpad. Aborting.\n");
 722                         return -1;
 723                 }
 724
 725                 pr_debug("Probably not a real Elantech touchpad. Enabling anyway due to force_elantech.\n");
 726         }
 727
 728         if (set_properties) {
 729                 psmouse->vendor = "Elantech";
 730                 psmouse->name = "Touchpad";
 731         }
 732
 733         return 0;
 734 }
 735
 736 /*
 737  * Clean up sysfs entries when disconnecting
 738  */
 739 static void elantech_disconnect(struct psmouse *psmouse)
 740 {
 741         sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
 742                            &elantech_attr_group);
 743         kfree(psmouse->private);
 744         psmouse->private = NULL;
 745 }
 746
 747 /*
 748  * Put the touchpad back into absolute mode when reconnecting
 749  */
 750 static int elantech_reconnect(struct psmouse *psmouse)
 751 {
 752         if (elantech_detect(psmouse, 0))
 753                 return -1;
 754
 755         if (elantech_set_absolute_mode(psmouse)) {
 756                 pr_err("failed to put touchpad back into absolute mode.\n");
 757                 return -1;
 758         }
 759
 760         return 0;
 761 }
 762
 763 /*
 764  * Initialize the touchpad and create sysfs entries
 765  */
 766 int elantech_init(struct psmouse *psmouse)
 767 {
 768         struct elantech_data *etd;
 769         int i, error;
 770         unsigned char param[3];
 771
 772         psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
 773         if (!etd)
 774                 return -ENOMEM;
 775
 776         etd->parity[0] = 1;
 777         for (i = 1; i < 256; i++)
 778                 etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
 779
 780         /*
 781          * Do the version query again so we can store the result
 782          */
 783         if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
 784                 pr_err("failed to query firmware version.\n");
 785                 goto init_fail;
 786         }
 787
 788         etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
 789
 790         /*
 791          * Assume every version greater than this is new EeePC style
 792          * hardware with 6 byte packets
 793          */
 794         if (etd->fw_version >= 0x020030) {
 795                 etd->hw_version = 2;
 796                 /* For now show extra debug information */
 797                 etd->debug = 1;
 798                 /* Don't know how to do parity checking for version 2 */
 799                 etd->paritycheck = 0;
 800
 801                 if (etd->fw_version >= 0x020800)
 802                         etd->reports_pressure = true;
 803
 804         } else {
 805                 etd->hw_version = 1;
 806                 etd->paritycheck = 1;
 807         }
 808
 809         pr_info("assuming hardware version %d, firmware version %d.%d.%d\n",
 810                 etd->hw_version, param[0], param[1], param[2]);
 811
 812         if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY,
 813             etd->capabilities)) {
 814                 pr_err("failed to query capabilities.\n");
 815                 goto init_fail;
 816         }
 817         pr_info("Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
 818                 etd->capabilities[0], etd->capabilities[1],
 819                 etd->capabilities[2]);
 820
 821         /*
 822          * This firmware suffers from misreporting coordinates when
 823          * a touch action starts causing the mouse cursor or scrolled page
 824          * to jump. Enable a workaround.
 825          */
 826         if (etd->fw_version == 0x020022 || etd->fw_version == 0x020600) {
 827                 pr_info("firmware version 2.0.34/2.6.0 detected, enabling jumpy cursor workaround\n");
 828                 etd->jumpy_cursor = true;
 829         }
 830
 831         if (elantech_set_absolute_mode(psmouse)) {
 832                 pr_err("failed to put touchpad into absolute mode.\n");
 833                 goto init_fail;
 834         }
 835
 836         elantech_set_input_params(psmouse);
 837
 838         error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
 839                                    &elantech_attr_group);
 840         if (error) {
 841                 pr_err("failed to create sysfs attributes, error: %d.\n", error);
 842                 goto init_fail;
 843         }
 844
 845         psmouse->protocol_handler = elantech_process_byte;
 846         psmouse->disconnect = elantech_disconnect;
 847         psmouse->reconnect = elantech_reconnect;
 848         psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
 849
 850         return 0;
 851
 852  init_fail:
 853         kfree(etd);
 854         return -1;
 855 }