drivers/input/touchscreen/zforce_ts.c

   1 /*
   2  * Copyright (C) 2012-2013 MundoReader S.L.
   3  * Author: Heiko Stuebner <heiko@sntech.de>
   4  *
   5  * based in parts on Nook zforce driver
   6  *
   7  * Copyright (C) 2010 Barnes & Noble, Inc.
   8  * Author: Pieter Truter<ptruter@intrinsyc.com>
   9  *
  10  * This software is licensed under the terms of the GNU General Public
  11  * License version 2, as published by the Free Software Foundation, and
  12  * may be copied, distributed, and modified under those terms.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/hrtimer.h>
  22 #include <linux/slab.h>
  23 #include <linux/input.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/i2c.h>
  26 #include <linux/delay.h>
  27 #include <linux/gpio.h>
  28 #include <linux/device.h>
  29 #include <linux/sysfs.h>
  30 #include <linux/input/mt.h>
  31 #include <linux/platform_data/zforce_ts.h>
  32 #include <linux/regulator/consumer.h>
  33 #include <linux/delay.h>
  34 #include <linux/of.h>
  35 #include <linux/of_gpio.h>
  36
  37 #define WAIT_TIMEOUT            msecs_to_jiffies(1000)
  38
  39 #define FRAME_START             0xee
  40 #define FRAME_MAXSIZE           257
  41
  42 /* Offsets of the different parts of the payload the controller sends */
  43 #define PAYLOAD_HEADER          0
  44 #define PAYLOAD_LENGTH          1
  45 #define PAYLOAD_BODY            2
  46
  47 /* Response offsets */
  48 #define RESPONSE_ID             0
  49 #define RESPONSE_DATA           1
  50
  51 /* Commands */
  52 #define COMMAND_DEACTIVATE      0x00
  53 #define COMMAND_INITIALIZE      0x01
  54 #define COMMAND_RESOLUTION      0x02
  55 #define COMMAND_SETCONFIG       0x03
  56 #define COMMAND_DATAREQUEST     0x04
  57 #define COMMAND_SCANFREQ        0x08
  58 #define COMMAND_STATUS          0X1e
  59
  60 /*
  61  * Responses the controller sends as a result of
  62  * command requests
  63  */
  64 #define RESPONSE_DEACTIVATE     0x00
  65 #define RESPONSE_INITIALIZE     0x01
  66 #define RESPONSE_RESOLUTION     0x02
  67 #define RESPONSE_SETCONFIG      0x03
  68 #define RESPONSE_SCANFREQ       0x08
  69 #define RESPONSE_STATUS         0X1e
  70
  71 /*
  72  * Notifications are sent by the touch controller without
  73  * being requested by the driver and include for example
  74  * touch indications
  75  */
  76 #define NOTIFICATION_TOUCH              0x04
  77 #define NOTIFICATION_BOOTCOMPLETE       0x07
  78 #define NOTIFICATION_OVERRUN            0x25
  79 #define NOTIFICATION_PROXIMITY          0x26
  80 #define NOTIFICATION_INVALID_COMMAND    0xfe
  81
  82 #define ZFORCE_REPORT_POINTS            2
  83 #define ZFORCE_MAX_AREA                 0xff
  84
  85 #define STATE_DOWN                      0
  86 #define STATE_MOVE                      1
  87 #define STATE_UP                        2
  88
  89 #define SETCONFIG_DUALTOUCH             (1 << 0)
  90
  91 struct zforce_point {
  92         int coord_x;
  93         int coord_y;
  94         int state;
  95         int id;
  96         int area_major;
  97         int area_minor;
  98         int orientation;
  99         int pressure;
 100         int prblty;
 101 };
 102
 103 /*
 104  * @client              the i2c_client
 105  * @input               the input device
 106  * @suspending          in the process of going to suspend (don't emit wakeup
 107  *                      events for commands executed to suspend the device)
 108  * @suspended           device suspended
 109  * @access_mutex        serialize i2c-access, to keep multipart reads together
 110  * @command_done        completion to wait for the command result
 111  * @command_mutex       serialize commands sent to the ic
 112  * @command_waiting     the id of the command that is currently waiting
 113  *                      for a result
 114  * @command_result      returned result of the command
 115  */
 116 struct zforce_ts {
 117         struct i2c_client       *client;
 118         struct input_dev        *input;
 119         const struct zforce_ts_platdata *pdata;
 120         char                    phys[32];
 121
 122         struct regulator        *reg_vdd;
 123
 124         bool                    suspending;
 125         bool                    suspended;
 126         bool                    boot_complete;
 127
 128         /* Firmware version information */
 129         u16                     version_major;
 130         u16                     version_minor;
 131         u16                     version_build;
 132         u16                     version_rev;
 133
 134         struct mutex            access_mutex;
 135
 136         struct completion       command_done;
 137         struct mutex            command_mutex;
 138         int                     command_waiting;
 139         int                     command_result;
 140 };
 141
 142 static int zforce_command(struct zforce_ts *ts, u8 cmd)
 143 {
 144         struct i2c_client *client = ts->client;
 145         char buf[3];
 146         int ret;
 147
 148         dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
 149
 150         buf[0] = FRAME_START;
 151         buf[1] = 1; /* data size, command only */
 152         buf[2] = cmd;
 153
 154         mutex_lock(&ts->access_mutex);
 155         ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
 156         mutex_unlock(&ts->access_mutex);
 157         if (ret < 0) {
 158                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 159                 return ret;
 160         }
 161
 162         return 0;
 163 }
 164
 165 static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
 166 {
 167         struct i2c_client *client = ts->client;
 168         int ret;
 169
 170         ret = mutex_trylock(&ts->command_mutex);
 171         if (!ret) {
 172                 dev_err(&client->dev, "already waiting for a command\n");
 173                 return -EBUSY;
 174         }
 175
 176         dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
 177                 buf[1], buf[2]);
 178
 179         ts->command_waiting = buf[2];
 180
 181         mutex_lock(&ts->access_mutex);
 182         ret = i2c_master_send(client, buf, len);
 183         mutex_unlock(&ts->access_mutex);
 184         if (ret < 0) {
 185                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 186                 goto unlock;
 187         }
 188
 189         dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
 190
 191         if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
 192                 ret = -ETIME;
 193                 goto unlock;
 194         }
 195
 196         ret = ts->command_result;
 197
 198 unlock:
 199         mutex_unlock(&ts->command_mutex);
 200         return ret;
 201 }
 202
 203 static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
 204 {
 205         struct i2c_client *client = ts->client;
 206         char buf[3];
 207         int ret;
 208
 209         dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
 210
 211         buf[0] = FRAME_START;
 212         buf[1] = 1; /* data size, command only */
 213         buf[2] = cmd;
 214
 215         ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 216         if (ret < 0) {
 217                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 218                 return ret;
 219         }
 220
 221         return 0;
 222 }
 223
 224 static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
 225 {
 226         struct i2c_client *client = ts->client;
 227         char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
 228                         (x & 0xff), ((x >> 8) & 0xff),
 229                         (y & 0xff), ((y >> 8) & 0xff) };
 230
 231         dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
 232
 233         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 234 }
 235
 236 static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
 237                                  u16 stylus)
 238 {
 239         struct i2c_client *client = ts->client;
 240         char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
 241                         (idle & 0xff), ((idle >> 8) & 0xff),
 242                         (finger & 0xff), ((finger >> 8) & 0xff),
 243                         (stylus & 0xff), ((stylus >> 8) & 0xff) };
 244
 245         dev_dbg(&client->dev,
 246                 "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
 247                 idle, finger, stylus);
 248
 249         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 250 }
 251
 252 static int zforce_setconfig(struct zforce_ts *ts, char b1)
 253 {
 254         struct i2c_client *client = ts->client;
 255         char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
 256                         b1, 0, 0, 0 };
 257
 258         dev_dbg(&client->dev, "set config to (%d)\n", b1);
 259
 260         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 261 }
 262
 263 static int zforce_start(struct zforce_ts *ts)
 264 {
 265         struct i2c_client *client = ts->client;
 266         const struct zforce_ts_platdata *pdata = ts->pdata;
 267         int ret;
 268
 269         dev_dbg(&client->dev, "starting device\n");
 270
 271         ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
 272         if (ret) {
 273                 dev_err(&client->dev, "Unable to initialize, %d\n", ret);
 274                 return ret;
 275         }
 276
 277         ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
 278         if (ret) {
 279                 dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
 280                 goto error;
 281         }
 282
 283         ret = zforce_scan_frequency(ts, 10, 50, 50);
 284         if (ret) {
 285                 dev_err(&client->dev, "Unable to set scan frequency, %d\n",
 286                         ret);
 287                 goto error;
 288         }
 289
 290         ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
 291         if (ret) {
 292                 dev_err(&client->dev, "Unable to set config\n");
 293                 goto error;
 294         }
 295
 296         /* start sending touch events */
 297         ret = zforce_command(ts, COMMAND_DATAREQUEST);
 298         if (ret) {
 299                 dev_err(&client->dev, "Unable to request data\n");
 300                 goto error;
 301         }
 302
 303         /*
 304          * Per NN, initial cal. take max. of 200msec.
 305          * Allow time to complete this calibration
 306          */
 307         msleep(200);
 308
 309         return 0;
 310
 311 error:
 312         zforce_command_wait(ts, COMMAND_DEACTIVATE);
 313         return ret;
 314 }
 315
 316 static int zforce_stop(struct zforce_ts *ts)
 317 {
 318         struct i2c_client *client = ts->client;
 319         int ret;
 320
 321         dev_dbg(&client->dev, "stopping device\n");
 322
 323         /* Deactivates touch sensing and puts the device into sleep. */
 324         ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
 325         if (ret != 0) {
 326                 dev_err(&client->dev, "could not deactivate device, %d\n",
 327                         ret);
 328                 return ret;
 329         }
 330
 331         return 0;
 332 }
 333
 334 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
 335 {
 336         struct i2c_client *client = ts->client;
 337         const struct zforce_ts_platdata *pdata = ts->pdata;
 338         struct zforce_point point;
 339         int count, i, num = 0;
 340
 341         count = payload[0];
 342         if (count > ZFORCE_REPORT_POINTS) {
 343                 dev_warn(&client->dev,
 344                          "too many coordinates %d, expected max %d\n",
 345                          count, ZFORCE_REPORT_POINTS);
 346                 count = ZFORCE_REPORT_POINTS;
 347         }
 348
 349         for (i = 0; i < count; i++) {
 350                 point.coord_x =
 351                         payload[9 * i + 2] << 8 | payload[9 * i + 1];
 352                 point.coord_y =
 353                         payload[9 * i + 4] << 8 | payload[9 * i + 3];
 354
 355                 if (point.coord_x > pdata->x_max ||
 356                     point.coord_y > pdata->y_max) {
 357                         dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
 358                                 point.coord_x, point.coord_y);
 359                         point.coord_x = point.coord_y = 0;
 360                 }
 361
 362                 point.state = payload[9 * i + 5] & 0x03;
 363                 point.id = (payload[9 * i + 5] & 0xfc) >> 2;
 364
 365                 /* determine touch major, minor and orientation */
 366                 point.area_major = max(payload[9 * i + 6],
 367                                           payload[9 * i + 7]);
 368                 point.area_minor = min(payload[9 * i + 6],
 369                                           payload[9 * i + 7]);
 370                 point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
 371
 372                 point.pressure = payload[9 * i + 8];
 373                 point.prblty = payload[9 * i + 9];
 374
 375                 dev_dbg(&client->dev,
 376                         "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
 377                         i, count, point.state, point.id,
 378                         point.pressure, point.prblty,
 379                         point.coord_x, point.coord_y,
 380                         point.area_major, point.area_minor,
 381                         point.orientation);
 382
 383                 /* the zforce id starts with "1", so needs to be decreased */
 384                 input_mt_slot(ts->input, point.id - 1);
 385
 386                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
 387                                                 point.state != STATE_UP);
 388
 389                 if (point.state != STATE_UP) {
 390                         input_report_abs(ts->input, ABS_MT_POSITION_X,
 391                                          point.coord_x);
 392                         input_report_abs(ts->input, ABS_MT_POSITION_Y,
 393                                          point.coord_y);
 394                         input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
 395                                          point.area_major);
 396                         input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
 397                                          point.area_minor);
 398                         input_report_abs(ts->input, ABS_MT_ORIENTATION,
 399                                          point.orientation);
 400                         num++;
 401                 }
 402         }
 403
 404         input_mt_sync_frame(ts->input);
 405
 406         input_mt_report_finger_count(ts->input, num);
 407
 408         input_sync(ts->input);
 409
 410         return 0;
 411 }
 412
 413 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
 414 {
 415         struct i2c_client *client = ts->client;
 416         int ret;
 417
 418         mutex_lock(&ts->access_mutex);
 419
 420         /* read 2 byte message header */
 421         ret = i2c_master_recv(client, buf, 2);
 422         if (ret < 0) {
 423                 dev_err(&client->dev, "error reading header: %d\n", ret);
 424                 goto unlock;
 425         }
 426
 427         if (buf[PAYLOAD_HEADER] != FRAME_START) {
 428                 dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
 429                 ret = -EIO;
 430                 goto unlock;
 431         }
 432
 433         if (buf[PAYLOAD_LENGTH] == 0) {
 434                 dev_err(&client->dev, "invalid payload length: %d\n",
 435                         buf[PAYLOAD_LENGTH]);
 436                 ret = -EIO;
 437                 goto unlock;
 438         }
 439
 440         /* read the message */
 441         ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
 442         if (ret < 0) {
 443                 dev_err(&client->dev, "error reading payload: %d\n", ret);
 444                 goto unlock;
 445         }
 446
 447         dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
 448                 buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
 449
 450 unlock:
 451         mutex_unlock(&ts->access_mutex);
 452         return ret;
 453 }
 454
 455 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
 456 {
 457         struct i2c_client *client = ts->client;
 458
 459         if (ts->command_waiting == cmd) {
 460                 dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
 461                 ts->command_result = result;
 462                 complete(&ts->command_done);
 463         } else {
 464                 dev_dbg(&client->dev, "command %d not for us\n", cmd);
 465         }
 466 }
 467
 468 static irqreturn_t zforce_irq(int irq, void *dev_id)
 469 {
 470         struct zforce_ts *ts = dev_id;
 471         struct i2c_client *client = ts->client;
 472
 473         if (ts->suspended && device_may_wakeup(&client->dev))
 474                 pm_wakeup_event(&client->dev, 500);
 475
 476         return IRQ_WAKE_THREAD;
 477 }
 478
 479 static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
 480 {
 481         struct zforce_ts *ts = dev_id;
 482         struct i2c_client *client = ts->client;
 483         const struct zforce_ts_platdata *pdata = ts->pdata;
 484         int ret;
 485         u8 payload_buffer[FRAME_MAXSIZE];
 486         u8 *payload;
 487
 488         /*
 489          * When still suspended, return.
 490          * Due to the level-interrupt we will get re-triggered later.
 491          */
 492         if (ts->suspended) {
 493                 msleep(20);
 494                 return IRQ_HANDLED;
 495         }
 496
 497         dev_dbg(&client->dev, "handling interrupt\n");
 498
 499         /* Don't emit wakeup events from commands run by zforce_suspend */
 500         if (!ts->suspending && device_may_wakeup(&client->dev))
 501                 pm_stay_awake(&client->dev);
 502
 503         while (!gpio_get_value(pdata->gpio_int)) {
 504                 ret = zforce_read_packet(ts, payload_buffer);
 505                 if (ret < 0) {
 506                         dev_err(&client->dev,
 507                                 "could not read packet, ret: %d\n", ret);
 508                         break;
 509                 }
 510
 511                 payload =  &payload_buffer[PAYLOAD_BODY];
 512
 513                 switch (payload[RESPONSE_ID]) {
 514                 case NOTIFICATION_TOUCH:
 515                         /*
 516                          * Always report touch-events received while
 517                          * suspending, when being a wakeup source
 518                          */
 519                         if (ts->suspending && device_may_wakeup(&client->dev))
 520                                 pm_wakeup_event(&client->dev, 500);
 521                         zforce_touch_event(ts, &payload[RESPONSE_DATA]);
 522                         break;
 523
 524                 case NOTIFICATION_BOOTCOMPLETE:
 525                         ts->boot_complete = payload[RESPONSE_DATA];
 526                         zforce_complete(ts, payload[RESPONSE_ID], 0);
 527                         break;
 528
 529                 case RESPONSE_INITIALIZE:
 530                 case RESPONSE_DEACTIVATE:
 531                 case RESPONSE_SETCONFIG:
 532                 case RESPONSE_RESOLUTION:
 533                 case RESPONSE_SCANFREQ:
 534                         zforce_complete(ts, payload[RESPONSE_ID],
 535                                         payload[RESPONSE_DATA]);
 536                         break;
 537
 538                 case RESPONSE_STATUS:
 539                         /*
 540                          * Version Payload Results
 541                          * [2:major] [2:minor] [2:build] [2:rev]
 542                          */
 543                         ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
 544                                                 payload[RESPONSE_DATA];
 545                         ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
 546                                                 payload[RESPONSE_DATA + 2];
 547                         ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
 548                                                 payload[RESPONSE_DATA + 4];
 549                         ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
 550                                                 payload[RESPONSE_DATA + 6];
 551                         dev_dbg(&ts->client->dev,
 552                                 "Firmware Version %04x:%04x %04x:%04x\n",
 553                                 ts->version_major, ts->version_minor,
 554                                 ts->version_build, ts->version_rev);
 555
 556                         zforce_complete(ts, payload[RESPONSE_ID], 0);
 557                         break;
 558
 559                 case NOTIFICATION_INVALID_COMMAND:
 560                         dev_err(&ts->client->dev, "invalid command: 0x%x\n",
 561                                 payload[RESPONSE_DATA]);
 562                         break;
 563
 564                 default:
 565                         dev_err(&ts->client->dev,
 566                                 "unrecognized response id: 0x%x\n",
 567                                 payload[RESPONSE_ID]);
 568                         break;
 569                 }
 570         }
 571
 572         if (!ts->suspending && device_may_wakeup(&client->dev))
 573                 pm_relax(&client->dev);
 574
 575         dev_dbg(&client->dev, "finished interrupt\n");
 576
 577         return IRQ_HANDLED;
 578 }
 579
 580 static int zforce_input_open(struct input_dev *dev)
 581 {
 582         struct zforce_ts *ts = input_get_drvdata(dev);
 583         int ret;
 584
 585         ret = zforce_start(ts);
 586         if (ret)
 587                 return ret;
 588
 589         return 0;
 590 }
 591
 592 static void zforce_input_close(struct input_dev *dev)
 593 {
 594         struct zforce_ts *ts = input_get_drvdata(dev);
 595         struct i2c_client *client = ts->client;
 596         int ret;
 597
 598         ret = zforce_stop(ts);
 599         if (ret)
 600                 dev_warn(&client->dev, "stopping zforce failed\n");
 601
 602         return;
 603 }
 604
 605 static int __maybe_unused zforce_suspend(struct device *dev)
 606 {
 607         struct i2c_client *client = to_i2c_client(dev);
 608         struct zforce_ts *ts = i2c_get_clientdata(client);
 609         struct input_dev *input = ts->input;
 610         int ret = 0;
 611
 612         mutex_lock(&input->mutex);
 613         ts->suspending = true;
 614
 615         /*
 616          * When configured as a wakeup source device should always wake
 617          * the system, therefore start device if necessary.
 618          */
 619         if (device_may_wakeup(&client->dev)) {
 620                 dev_dbg(&client->dev, "suspend while being a wakeup source\n");
 621
 622                 /* Need to start device, if not open, to be a wakeup source. */
 623                 if (!input->users) {
 624                         ret = zforce_start(ts);
 625                         if (ret)
 626                                 goto unlock;
 627                 }
 628
 629                 enable_irq_wake(client->irq);
 630         } else if (input->users) {
 631                 dev_dbg(&client->dev,
 632                         "suspend without being a wakeup source\n");
 633
 634                 ret = zforce_stop(ts);
 635                 if (ret)
 636                         goto unlock;
 637
 638                 disable_irq(client->irq);
 639         }
 640
 641         ts->suspended = true;
 642
 643 unlock:
 644         ts->suspending = false;
 645         mutex_unlock(&input->mutex);
 646
 647         return ret;
 648 }
 649
 650 static int __maybe_unused zforce_resume(struct device *dev)
 651 {
 652         struct i2c_client *client = to_i2c_client(dev);
 653         struct zforce_ts *ts = i2c_get_clientdata(client);
 654         struct input_dev *input = ts->input;
 655         int ret = 0;
 656
 657         mutex_lock(&input->mutex);
 658
 659         ts->suspended = false;
 660
 661         if (device_may_wakeup(&client->dev)) {
 662                 dev_dbg(&client->dev, "resume from being a wakeup source\n");
 663
 664                 disable_irq_wake(client->irq);
 665
 666                 /* need to stop device if it was not open on suspend */
 667                 if (!input->users) {
 668                         ret = zforce_stop(ts);
 669                         if (ret)
 670                                 goto unlock;
 671                 }
 672         } else if (input->users) {
 673                 dev_dbg(&client->dev, "resume without being a wakeup source\n");
 674
 675                 enable_irq(client->irq);
 676
 677                 ret = zforce_start(ts);
 678                 if (ret < 0)
 679                         goto unlock;
 680         }
 681
 682 unlock:
 683         mutex_unlock(&input->mutex);
 684
 685         return ret;
 686 }
 687
 688 static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
 689
 690 static void zforce_reset(void *data)
 691 {
 692         struct zforce_ts *ts = data;
 693
 694         gpio_set_value(ts->pdata->gpio_rst, 0);
 695
 696         udelay(10);
 697
 698         if (!IS_ERR(ts->reg_vdd))
 699                 regulator_disable(ts->reg_vdd);
 700 }
 701
 702 static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
 703 {
 704         struct zforce_ts_platdata *pdata;
 705         struct device_node *np = dev->of_node;
 706
 707         if (!np)
 708                 return ERR_PTR(-ENOENT);
 709
 710         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 711         if (!pdata) {
 712                 dev_err(dev, "failed to allocate platform data\n");
 713                 return ERR_PTR(-ENOMEM);
 714         }
 715
 716         pdata->gpio_int = of_get_gpio(np, 0);
 717         if (!gpio_is_valid(pdata->gpio_int)) {
 718                 dev_err(dev, "failed to get interrupt gpio\n");
 719                 return ERR_PTR(-EINVAL);
 720         }
 721
 722         pdata->gpio_rst = of_get_gpio(np, 1);
 723         if (!gpio_is_valid(pdata->gpio_rst)) {
 724                 dev_err(dev, "failed to get reset gpio\n");
 725                 return ERR_PTR(-EINVAL);
 726         }
 727
 728         if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
 729                 dev_err(dev, "failed to get x-size property\n");
 730                 return ERR_PTR(-EINVAL);
 731         }
 732
 733         if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
 734                 dev_err(dev, "failed to get y-size property\n");
 735                 return ERR_PTR(-EINVAL);
 736         }
 737
 738         return pdata;
 739 }
 740
 741 static int zforce_probe(struct i2c_client *client,
 742                         const struct i2c_device_id *id)
 743 {
 744         const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
 745         struct zforce_ts *ts;
 746         struct input_dev *input_dev;
 747         int ret;
 748
 749         if (!pdata) {
 750                 pdata = zforce_parse_dt(&client->dev);
 751                 if (IS_ERR(pdata))
 752                         return PTR_ERR(pdata);
 753         }
 754
 755         ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
 756         if (!ts)
 757                 return -ENOMEM;
 758
 759         ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
 760                                     "zforce_ts_int");
 761         if (ret) {
 762                 dev_err(&client->dev, "request of gpio %d failed, %d\n",
 763                         pdata->gpio_int, ret);
 764                 return ret;
 765         }
 766
 767         ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
 768                                     GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
 769         if (ret) {
 770                 dev_err(&client->dev, "request of gpio %d failed, %d\n",
 771                         pdata->gpio_rst, ret);
 772                 return ret;
 773         }
 774
 775         ts->reg_vdd = devm_regulator_get_optional(&client->dev, "vdd");
 776         if (IS_ERR(ts->reg_vdd)) {
 777                 ret = PTR_ERR(ts->reg_vdd);
 778                 if (ret == -EPROBE_DEFER)
 779                         return ret;
 780         } else {
 781                 ret = regulator_enable(ts->reg_vdd);
 782                 if (ret)
 783                         return ret;
 784
 785                 /*
 786                  * according to datasheet add 100us grace time after regular
 787                  * regulator enable delay.
 788                  */
 789                 udelay(100);
 790         }
 791
 792         ret = devm_add_action(&client->dev, zforce_reset, ts);
 793         if (ret) {
 794                 dev_err(&client->dev, "failed to register reset action, %d\n",
 795                         ret);
 796
 797                 /* hereafter the regulator will be disabled by the action */
 798                 if (!IS_ERR(ts->reg_vdd))
 799                         regulator_disable(ts->reg_vdd);
 800
 801                 return ret;
 802         }
 803
 804         snprintf(ts->phys, sizeof(ts->phys),
 805                  "%s/input0", dev_name(&client->dev));
 806
 807         input_dev = devm_input_allocate_device(&client->dev);
 808         if (!input_dev) {
 809                 dev_err(&client->dev, "could not allocate input device\n");
 810                 return -ENOMEM;
 811         }
 812
 813         mutex_init(&ts->access_mutex);
 814         mutex_init(&ts->command_mutex);
 815
 816         ts->pdata = pdata;
 817         ts->client = client;
 818         ts->input = input_dev;
 819
 820         input_dev->name = "Neonode zForce touchscreen";
 821         input_dev->phys = ts->phys;
 822         input_dev->id.bustype = BUS_I2C;
 823
 824         input_dev->open = zforce_input_open;
 825         input_dev->close = zforce_input_close;
 826
 827         __set_bit(EV_KEY, input_dev->evbit);
 828         __set_bit(EV_SYN, input_dev->evbit);
 829         __set_bit(EV_ABS, input_dev->evbit);
 830
 831         /* For multi touch */
 832         input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
 833                              pdata->x_max, 0, 0);
 834         input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
 835                              pdata->y_max, 0, 0);
 836
 837         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 838                              ZFORCE_MAX_AREA, 0, 0);
 839         input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
 840                              ZFORCE_MAX_AREA, 0, 0);
 841         input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
 842         input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
 843
 844         input_set_drvdata(ts->input, ts);
 845
 846         init_completion(&ts->command_done);
 847
 848         /*
 849          * The zforce pulls the interrupt low when it has data ready.
 850          * After it is triggered the isr thread runs until all the available
 851          * packets have been read and the interrupt is high again.
 852          * Therefore we can trigger the interrupt anytime it is low and do
 853          * not need to limit it to the interrupt edge.
 854          */
 855         ret = devm_request_threaded_irq(&client->dev, client->irq,
 856                                         zforce_irq, zforce_irq_thread,
 857                                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 858                                         input_dev->name, ts);
 859         if (ret) {
 860                 dev_err(&client->dev, "irq %d request failed\n", client->irq);
 861                 return ret;
 862         }
 863
 864         i2c_set_clientdata(client, ts);
 865
 866         /* let the controller boot */
 867         gpio_set_value(pdata->gpio_rst, 1);
 868
 869         ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
 870         if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
 871                 dev_warn(&client->dev, "bootcomplete timed out\n");
 872
 873         /* need to start device to get version information */
 874         ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
 875         if (ret) {
 876                 dev_err(&client->dev, "unable to initialize, %d\n", ret);
 877                 return ret;
 878         }
 879
 880         /* this gets the firmware version among other information */
 881         ret = zforce_command_wait(ts, COMMAND_STATUS);
 882         if (ret < 0) {
 883                 dev_err(&client->dev, "couldn't get status, %d\n", ret);
 884                 zforce_stop(ts);
 885                 return ret;
 886         }
 887
 888         /* stop device and put it into sleep until it is opened */
 889         ret = zforce_stop(ts);
 890         if (ret < 0)
 891                 return ret;
 892
 893         device_set_wakeup_capable(&client->dev, true);
 894
 895         ret = input_register_device(input_dev);
 896         if (ret) {
 897                 dev_err(&client->dev, "could not register input device, %d\n",
 898                         ret);
 899                 return ret;
 900         }
 901
 902         return 0;
 903 }
 904
 905 static struct i2c_device_id zforce_idtable[] = {
 906         { "zforce-ts", 0 },
 907         { }
 908 };
 909 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
 910
 911 #ifdef CONFIG_OF
 912 static const struct of_device_id zforce_dt_idtable[] = {
 913         { .compatible = "neonode,zforce" },
 914         {},
 915 };
 916 MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
 917 #endif
 918
 919 static struct i2c_driver zforce_driver = {
 920         .driver = {
 921                 .owner  = THIS_MODULE,
 922                 .name   = "zforce-ts",
 923                 .pm     = &zforce_pm_ops,
 924                 .of_match_table = of_match_ptr(zforce_dt_idtable),
 925         },
 926         .probe          = zforce_probe,
 927         .id_table       = zforce_idtable,
 928 };
 929
 930 module_i2c_driver(zforce_driver);
 931
 932 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 933 MODULE_DESCRIPTION("zForce TouchScreen Driver");
 934 MODULE_LICENSE("GPL");