drivers/input/touchscreen/zforce_ts.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012-2013 MundoReader S.L.
   4  * Author: Heiko Stuebner <heiko@sntech.de>
   5  *
   6  * based in parts on Nook zforce driver
   7  *
   8  * Copyright (C) 2010 Barnes & Noble, Inc.
   9  * Author: Pieter Truter<ptruter@intrinsyc.com>
  10  */
  11
  12 #include <linux/delay.h>
  13 #include <linux/device.h>
  14 #include <linux/gpio/consumer.h>
  15 #include <linux/i2c.h>
  16 #include <linux/input.h>
  17 #include <linux/input/mt.h>
  18 #include <linux/input/touchscreen.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/property.h>
  23 #include <linux/regulator/consumer.h>
  24 #include <linux/slab.h>
  25 #include <linux/unaligned.h>
  26
  27 #define WAIT_TIMEOUT            msecs_to_jiffies(1000)
  28
  29 #define FRAME_START             0xee
  30 #define FRAME_MAXSIZE           257
  31
  32 /* Offsets of the different parts of the payload the controller sends */
  33 #define PAYLOAD_HEADER          0
  34 #define PAYLOAD_LENGTH          1
  35 #define PAYLOAD_BODY            2
  36
  37 /* Response offsets */
  38 #define RESPONSE_ID             0
  39 #define RESPONSE_DATA           1
  40
  41 /* Commands */
  42 #define COMMAND_DEACTIVATE      0x00
  43 #define COMMAND_INITIALIZE      0x01
  44 #define COMMAND_RESOLUTION      0x02
  45 #define COMMAND_SETCONFIG       0x03
  46 #define COMMAND_DATAREQUEST     0x04
  47 #define COMMAND_SCANFREQ        0x08
  48 #define COMMAND_STATUS          0X1e
  49
  50 /*
  51  * Responses the controller sends as a result of
  52  * command requests
  53  */
  54 #define RESPONSE_DEACTIVATE     0x00
  55 #define RESPONSE_INITIALIZE     0x01
  56 #define RESPONSE_RESOLUTION     0x02
  57 #define RESPONSE_SETCONFIG      0x03
  58 #define RESPONSE_SCANFREQ       0x08
  59 #define RESPONSE_STATUS         0X1e
  60
  61 /*
  62  * Notifications are sent by the touch controller without
  63  * being requested by the driver and include for example
  64  * touch indications
  65  */
  66 #define NOTIFICATION_TOUCH              0x04
  67 #define NOTIFICATION_BOOTCOMPLETE       0x07
  68 #define NOTIFICATION_OVERRUN            0x25
  69 #define NOTIFICATION_PROXIMITY          0x26
  70 #define NOTIFICATION_INVALID_COMMAND    0xfe
  71
  72 #define ZFORCE_REPORT_POINTS            2
  73 #define ZFORCE_MAX_AREA                 0xff
  74
  75 #define STATE_DOWN                      0
  76 #define STATE_MOVE                      1
  77 #define STATE_UP                        2
  78
  79 #define SETCONFIG_DUALTOUCH             (1 << 0)
  80
  81 struct zforce_point {
  82         int coord_x;
  83         int coord_y;
  84         int state;
  85         int id;
  86         int area_major;
  87         int area_minor;
  88         int orientation;
  89         int pressure;
  90         int prblty;
  91 };
  92
  93 /*
  94  * @client              the i2c_client
  95  * @input               the input device
  96  * @suspending          in the process of going to suspend (don't emit wakeup
  97  *                      events for commands executed to suspend the device)
  98  * @suspended           device suspended
  99  * @command_done        completion to wait for the command result
 100  * @command_waiting     the id of the command that is currently waiting
 101  *                      for a result
 102  * @command_result      returned result of the command
 103  */
 104 struct zforce_ts {
 105         struct i2c_client       *client;
 106         struct input_dev        *input;
 107         struct touchscreen_properties prop;
 108         char                    phys[32];
 109
 110         struct gpio_desc        *gpio_int;
 111         struct gpio_desc        *gpio_rst;
 112
 113         bool                    suspending;
 114         bool                    suspended;
 115         bool                    boot_complete;
 116
 117         /* Firmware version information */
 118         u16                     version_major;
 119         u16                     version_minor;
 120         u16                     version_build;
 121         u16                     version_rev;
 122
 123         struct completion       command_done;
 124         int                     command_waiting;
 125         int                     command_result;
 126 };
 127
 128 static int zforce_command(struct zforce_ts *ts, u8 cmd)
 129 {
 130         struct i2c_client *client = ts->client;
 131         char buf[3];
 132         int ret;
 133
 134         dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
 135
 136         buf[0] = FRAME_START;
 137         buf[1] = 1; /* data size, command only */
 138         buf[2] = cmd;
 139
 140         ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
 141         if (ret < 0) {
 142                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 143                 return ret;
 144         }
 145
 146         return 0;
 147 }
 148
 149 static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
 150 {
 151         struct i2c_client *client = ts->client;
 152         int ret;
 153
 154         dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
 155                 buf[1], buf[2]);
 156
 157         ts->command_waiting = buf[2];
 158
 159         ret = i2c_master_send(client, buf, len);
 160         if (ret < 0) {
 161                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 162                 return ret;
 163         }
 164
 165         dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
 166
 167         if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
 168                 return -ETIME;
 169
 170         ret = ts->command_result;
 171         return 0;
 172 }
 173
 174 static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
 175 {
 176         struct i2c_client *client = ts->client;
 177         char buf[3];
 178         int error;
 179
 180         dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
 181
 182         buf[0] = FRAME_START;
 183         buf[1] = 1; /* data size, command only */
 184         buf[2] = cmd;
 185
 186         error = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 187         if (error) {
 188                 dev_err(&client->dev, "i2c send data request error: %d\n",
 189                         error);
 190                 return error;
 191         }
 192
 193         return 0;
 194 }
 195
 196 static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
 197 {
 198         struct i2c_client *client = ts->client;
 199         char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
 200                         (x & 0xff), ((x >> 8) & 0xff),
 201                         (y & 0xff), ((y >> 8) & 0xff) };
 202
 203         dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
 204
 205         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 206 }
 207
 208 static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
 209                                  u16 stylus)
 210 {
 211         struct i2c_client *client = ts->client;
 212         char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
 213                         (idle & 0xff), ((idle >> 8) & 0xff),
 214                         (finger & 0xff), ((finger >> 8) & 0xff),
 215                         (stylus & 0xff), ((stylus >> 8) & 0xff) };
 216
 217         dev_dbg(&client->dev,
 218                 "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
 219                 idle, finger, stylus);
 220
 221         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 222 }
 223
 224 static int zforce_setconfig(struct zforce_ts *ts, char b1)
 225 {
 226         struct i2c_client *client = ts->client;
 227         char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
 228                         b1, 0, 0, 0 };
 229
 230         dev_dbg(&client->dev, "set config to (%d)\n", b1);
 231
 232         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 233 }
 234
 235 static int zforce_start(struct zforce_ts *ts)
 236 {
 237         struct i2c_client *client = ts->client;
 238         int error;
 239
 240         dev_dbg(&client->dev, "starting device\n");
 241
 242         error = zforce_command_wait(ts, COMMAND_INITIALIZE);
 243         if (error) {
 244                 dev_err(&client->dev, "Unable to initialize, %d\n", error);
 245                 return error;
 246         }
 247
 248         error = zforce_resolution(ts, ts->prop.max_x, ts->prop.max_y);
 249         if (error) {
 250                 dev_err(&client->dev, "Unable to set resolution, %d\n", error);
 251                 goto err_deactivate;
 252         }
 253
 254         error = zforce_scan_frequency(ts, 10, 50, 50);
 255         if (error) {
 256                 dev_err(&client->dev, "Unable to set scan frequency, %d\n",
 257                         error);
 258                 goto err_deactivate;
 259         }
 260
 261         error = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
 262         if (error) {
 263                 dev_err(&client->dev, "Unable to set config\n");
 264                 goto err_deactivate;
 265         }
 266
 267         /* start sending touch events */
 268         error = zforce_command(ts, COMMAND_DATAREQUEST);
 269         if (error) {
 270                 dev_err(&client->dev, "Unable to request data\n");
 271                 goto err_deactivate;
 272         }
 273
 274         /*
 275          * Per NN, initial cal. take max. of 200msec.
 276          * Allow time to complete this calibration
 277          */
 278         msleep(200);
 279
 280         return 0;
 281
 282 err_deactivate:
 283         zforce_command_wait(ts, COMMAND_DEACTIVATE);
 284         return error;
 285 }
 286
 287 static int zforce_stop(struct zforce_ts *ts)
 288 {
 289         struct i2c_client *client = ts->client;
 290         int error;
 291
 292         dev_dbg(&client->dev, "stopping device\n");
 293
 294         /* Deactivates touch sensing and puts the device into sleep. */
 295         error = zforce_command_wait(ts, COMMAND_DEACTIVATE);
 296         if (error) {
 297                 dev_err(&client->dev, "could not deactivate device, %d\n",
 298                         error);
 299                 return error;
 300         }
 301
 302         return 0;
 303 }
 304
 305 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
 306 {
 307         struct i2c_client *client = ts->client;
 308         struct zforce_point point;
 309         int count, i, num = 0;
 310         u8 *p;
 311
 312         count = payload[0];
 313         if (count > ZFORCE_REPORT_POINTS) {
 314                 dev_warn(&client->dev,
 315                          "too many coordinates %d, expected max %d\n",
 316                          count, ZFORCE_REPORT_POINTS);
 317                 count = ZFORCE_REPORT_POINTS;
 318         }
 319
 320         for (i = 0; i < count; i++) {
 321                 p = &payload[i * 9 + 1];
 322
 323                 point.coord_x = get_unaligned_le16(&p[0]);
 324                 point.coord_y = get_unaligned_le16(&p[2]);
 325
 326                 if (point.coord_x > ts->prop.max_x ||
 327                     point.coord_y > ts->prop.max_y) {
 328                         dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
 329                                 point.coord_x, point.coord_y);
 330                         point.coord_x = point.coord_y = 0;
 331                 }
 332
 333                 point.state = p[4] & 0x0f;
 334                 point.id = (p[4] & 0xf0) >> 4;
 335
 336                 /* determine touch major, minor and orientation */
 337                 point.area_major = max(p[5], p[6]);
 338                 point.area_minor = min(p[5], p[6]);
 339                 point.orientation = p[5] > p[6];
 340
 341                 point.pressure = p[7];
 342                 point.prblty = p[8];
 343
 344                 dev_dbg(&client->dev,
 345                         "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
 346                         i, count, point.state, point.id,
 347                         point.pressure, point.prblty,
 348                         point.coord_x, point.coord_y,
 349                         point.area_major, point.area_minor,
 350                         point.orientation);
 351
 352                 /* the zforce id starts with "1", so needs to be decreased */
 353                 input_mt_slot(ts->input, point.id - 1);
 354
 355                 if (input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
 356                                                point.state != STATE_UP)) {
 357                         touchscreen_report_pos(ts->input, &ts->prop,
 358                                                point.coord_x, point.coord_y,
 359                                                true);
 360                         input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
 361                                          point.area_major);
 362                         input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
 363                                          point.area_minor);
 364                         input_report_abs(ts->input, ABS_MT_ORIENTATION,
 365                                          point.orientation);
 366                         num++;
 367                 }
 368         }
 369
 370         input_mt_sync_frame(ts->input);
 371
 372         input_mt_report_finger_count(ts->input, num);
 373
 374         input_sync(ts->input);
 375
 376         return 0;
 377 }
 378
 379 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
 380 {
 381         struct i2c_client *client = ts->client;
 382         int ret;
 383
 384         /* read 2 byte message header */
 385         ret = i2c_master_recv(client, buf, 2);
 386         if (ret < 0) {
 387                 dev_err(&client->dev, "error reading header: %d\n", ret);
 388                 return ret;
 389         }
 390
 391         if (buf[PAYLOAD_HEADER] != FRAME_START) {
 392                 dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
 393                 return -EIO;
 394         }
 395
 396         if (buf[PAYLOAD_LENGTH] == 0) {
 397                 dev_err(&client->dev, "invalid payload length: %d\n",
 398                         buf[PAYLOAD_LENGTH]);
 399                 return -EIO;
 400         }
 401
 402         /* read the message */
 403         ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
 404         if (ret < 0) {
 405                 dev_err(&client->dev, "error reading payload: %d\n", ret);
 406                 return ret;
 407         }
 408
 409         dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
 410                 buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
 411
 412         return 0;
 413 }
 414
 415 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
 416 {
 417         struct i2c_client *client = ts->client;
 418
 419         if (ts->command_waiting == cmd) {
 420                 dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
 421                 ts->command_result = result;
 422                 complete(&ts->command_done);
 423         } else {
 424                 dev_dbg(&client->dev, "command %d not for us\n", cmd);
 425         }
 426 }
 427
 428 static irqreturn_t zforce_irq(int irq, void *dev_id)
 429 {
 430         struct zforce_ts *ts = dev_id;
 431         struct i2c_client *client = ts->client;
 432
 433         if (ts->suspended && device_may_wakeup(&client->dev))
 434                 pm_wakeup_event(&client->dev, 500);
 435
 436         return IRQ_WAKE_THREAD;
 437 }
 438
 439 static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
 440 {
 441         struct zforce_ts *ts = dev_id;
 442         struct i2c_client *client = ts->client;
 443         int error;
 444         u8 payload_buffer[FRAME_MAXSIZE];
 445         u8 *payload;
 446         bool suspending;
 447
 448         /*
 449          * When still suspended, return.
 450          * Due to the level-interrupt we will get re-triggered later.
 451          */
 452         if (ts->suspended) {
 453                 msleep(20);
 454                 return IRQ_HANDLED;
 455         }
 456
 457         dev_dbg(&client->dev, "handling interrupt\n");
 458
 459         /* Don't emit wakeup events from commands run by zforce_suspend */
 460         suspending = READ_ONCE(ts->suspending);
 461         if (!suspending && device_may_wakeup(&client->dev))
 462                 pm_stay_awake(&client->dev);
 463
 464         /*
 465          * Run at least once and exit the loop if
 466          * - the optional interrupt GPIO isn't specified
 467          *   (there is only one packet read per ISR invocation, then)
 468          * or
 469          * - the GPIO isn't active any more
 470          *   (packet read until the level GPIO indicates that there is
 471          *    no IRQ any more)
 472          */
 473         do {
 474                 error = zforce_read_packet(ts, payload_buffer);
 475                 if (error) {
 476                         dev_err(&client->dev,
 477                                 "could not read packet, ret: %d\n", error);
 478                         break;
 479                 }
 480
 481                 payload =  &payload_buffer[PAYLOAD_BODY];
 482
 483                 switch (payload[RESPONSE_ID]) {
 484                 case NOTIFICATION_TOUCH:
 485                         /*
 486                          * Always report touch-events received while
 487                          * suspending, when being a wakeup source
 488                          */
 489                         if (suspending && device_may_wakeup(&client->dev))
 490                                 pm_wakeup_event(&client->dev, 500);
 491                         zforce_touch_event(ts, &payload[RESPONSE_DATA]);
 492                         break;
 493
 494                 case NOTIFICATION_BOOTCOMPLETE:
 495                         ts->boot_complete = payload[RESPONSE_DATA];
 496                         zforce_complete(ts, payload[RESPONSE_ID], 0);
 497                         break;
 498
 499                 case RESPONSE_INITIALIZE:
 500                 case RESPONSE_DEACTIVATE:
 501                 case RESPONSE_SETCONFIG:
 502                 case RESPONSE_RESOLUTION:
 503                 case RESPONSE_SCANFREQ:
 504                         zforce_complete(ts, payload[RESPONSE_ID],
 505                                         payload[RESPONSE_DATA]);
 506                         break;
 507
 508                 case RESPONSE_STATUS:
 509                         /*
 510                          * Version Payload Results
 511                          * [2:major] [2:minor] [2:build] [2:rev]
 512                          */
 513                         ts->version_major =
 514                                 get_unaligned_le16(&payload[RESPONSE_DATA]);
 515                         ts->version_minor =
 516                                 get_unaligned_le16(&payload[RESPONSE_DATA + 2]);
 517                         ts->version_build =
 518                                 get_unaligned_le16(&payload[RESPONSE_DATA + 4]);
 519                         ts->version_rev =
 520                                 get_unaligned_le16(&payload[RESPONSE_DATA + 6]);
 521
 522                         dev_dbg(&ts->client->dev,
 523                                 "Firmware Version %04x:%04x %04x:%04x\n",
 524                                 ts->version_major, ts->version_minor,
 525                                 ts->version_build, ts->version_rev);
 526
 527                         zforce_complete(ts, payload[RESPONSE_ID], 0);
 528                         break;
 529
 530                 case NOTIFICATION_INVALID_COMMAND:
 531                         dev_err(&ts->client->dev, "invalid command: 0x%x\n",
 532                                 payload[RESPONSE_DATA]);
 533                         break;
 534
 535                 default:
 536                         dev_err(&ts->client->dev,
 537                                 "unrecognized response id: 0x%x\n",
 538                                 payload[RESPONSE_ID]);
 539                         break;
 540                 }
 541         } while (gpiod_get_value_cansleep(ts->gpio_int));
 542
 543         if (!suspending && device_may_wakeup(&client->dev))
 544                 pm_relax(&client->dev);
 545
 546         dev_dbg(&client->dev, "finished interrupt\n");
 547
 548         return IRQ_HANDLED;
 549 }
 550
 551 static int zforce_input_open(struct input_dev *dev)
 552 {
 553         struct zforce_ts *ts = input_get_drvdata(dev);
 554
 555         return zforce_start(ts);
 556 }
 557
 558 static void zforce_input_close(struct input_dev *dev)
 559 {
 560         struct zforce_ts *ts = input_get_drvdata(dev);
 561         struct i2c_client *client = ts->client;
 562         int error;
 563
 564         error = zforce_stop(ts);
 565         if (error)
 566                 dev_warn(&client->dev, "stopping zforce failed\n");
 567 }
 568
 569 static int __zforce_suspend(struct zforce_ts *ts)
 570 {
 571         struct i2c_client *client = ts->client;
 572         struct input_dev *input = ts->input;
 573         int error;
 574
 575         guard(mutex)(&input->mutex);
 576
 577         /*
 578          * When configured as a wakeup source device should always wake
 579          * the system, therefore start device if necessary.
 580          */
 581         if (device_may_wakeup(&client->dev)) {
 582                 dev_dbg(&client->dev, "suspend while being a wakeup source\n");
 583
 584                 /* Need to start device, if not open, to be a wakeup source. */
 585                 if (!input_device_enabled(input)) {
 586                         error = zforce_start(ts);
 587                         if (error)
 588                                 return error;
 589                 }
 590
 591                 enable_irq_wake(client->irq);
 592         } else if (input_device_enabled(input)) {
 593                 dev_dbg(&client->dev,
 594                         "suspend without being a wakeup source\n");
 595
 596                 error = zforce_stop(ts);
 597                 if (error)
 598                         return error;
 599
 600                 disable_irq(client->irq);
 601         }
 602
 603         ts->suspended = true;
 604         return 0;
 605 }
 606
 607 static int zforce_suspend(struct device *dev)
 608 {
 609         struct i2c_client *client = to_i2c_client(dev);
 610         struct zforce_ts *ts = i2c_get_clientdata(client);
 611         int ret;
 612
 613         WRITE_ONCE(ts->suspending, true);
 614         smp_mb();
 615
 616         ret = __zforce_suspend(ts);
 617
 618         smp_mb();
 619         WRITE_ONCE(ts->suspending, false);
 620
 621         return ret;
 622 }
 623
 624 static int zforce_resume(struct device *dev)
 625 {
 626         struct i2c_client *client = to_i2c_client(dev);
 627         struct zforce_ts *ts = i2c_get_clientdata(client);
 628         struct input_dev *input = ts->input;
 629         int error;
 630
 631         guard(mutex)(&input->mutex);
 632
 633         ts->suspended = false;
 634
 635         if (device_may_wakeup(&client->dev)) {
 636                 dev_dbg(&client->dev, "resume from being a wakeup source\n");
 637
 638                 disable_irq_wake(client->irq);
 639
 640                 /* need to stop device if it was not open on suspend */
 641                 if (!input_device_enabled(input)) {
 642                         error = zforce_stop(ts);
 643                         if (error)
 644                                 return error;
 645                 }
 646         } else if (input_device_enabled(input)) {
 647                 dev_dbg(&client->dev, "resume without being a wakeup source\n");
 648
 649                 enable_irq(client->irq);
 650
 651                 error = zforce_start(ts);
 652                 if (error)
 653                         return error;
 654         }
 655
 656         return 0;
 657 }
 658
 659 static DEFINE_SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
 660
 661 static void zforce_reset(void *data)
 662 {
 663         struct zforce_ts *ts = data;
 664
 665         gpiod_set_value_cansleep(ts->gpio_rst, 1);
 666         udelay(10);
 667 }
 668
 669 static void zforce_ts_parse_legacy_properties(struct zforce_ts *ts)
 670 {
 671         u32 x_max = 0;
 672         u32 y_max = 0;
 673
 674         device_property_read_u32(&ts->client->dev, "x-size", &x_max);
 675         input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, x_max, 0, 0);
 676
 677         device_property_read_u32(&ts->client->dev, "y-size", &y_max);
 678         input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, y_max, 0, 0);
 679 }
 680
 681 static int zforce_probe(struct i2c_client *client)
 682 {
 683         struct zforce_ts *ts;
 684         struct input_dev *input_dev;
 685         int error;
 686
 687         ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
 688         if (!ts)
 689                 return -ENOMEM;
 690
 691         ts->gpio_rst = devm_gpiod_get_optional(&client->dev, "reset",
 692                                                GPIOD_OUT_HIGH);
 693         error = PTR_ERR_OR_ZERO(ts->gpio_rst);
 694         if (error)
 695                 return dev_err_probe(&client->dev, error,
 696                                      "failed to request reset GPIO\n");
 697
 698         if (ts->gpio_rst) {
 699                 ts->gpio_int = devm_gpiod_get_optional(&client->dev, "irq",
 700                                                        GPIOD_IN);
 701                 error = PTR_ERR_OR_ZERO(ts->gpio_int);
 702                 if (error)
 703                         return dev_err_probe(&client->dev, error,
 704                                              "failed to request interrupt GPIO\n");
 705         } else {
 706                 /*
 707                  * Deprecated GPIO handling for compatibility
 708                  * with legacy binding.
 709                  */
 710
 711                 /* INT GPIO */
 712                 ts->gpio_int = devm_gpiod_get_index(&client->dev, NULL, 0,
 713                                                     GPIOD_IN);
 714
 715                 error = PTR_ERR_OR_ZERO(ts->gpio_int);
 716                 if (error)
 717                         return dev_err_probe(&client->dev, error,
 718                                              "failed to request interrupt GPIO\n");
 719
 720                 /* RST GPIO */
 721                 ts->gpio_rst = devm_gpiod_get_index(&client->dev, NULL, 1,
 722                                             GPIOD_OUT_HIGH);
 723                 error = PTR_ERR_OR_ZERO(ts->gpio_rst);
 724                 if (error)
 725                         return dev_err_probe(&client->dev, error,
 726                                              "failed to request reset GPIO\n");
 727         }
 728
 729         error = devm_regulator_get_enable(&client->dev, "vdd");
 730         if (error)
 731                 return dev_err_probe(&client->dev, error,
 732                                      "failed to request vdd supply\n");
 733
 734         /*
 735          * According to datasheet add 100us grace time after regular
 736          * regulator enable delay.
 737          */
 738         usleep_range(100, 200);
 739
 740         error = devm_add_action_or_reset(&client->dev, zforce_reset, ts);
 741         if (error)
 742                 return dev_err_probe(&client->dev, error,
 743                                      "failed to register reset action\n");
 744
 745         snprintf(ts->phys, sizeof(ts->phys),
 746                  "%s/input0", dev_name(&client->dev));
 747
 748         input_dev = devm_input_allocate_device(&client->dev);
 749         if (!input_dev)
 750                 return dev_err_probe(&client->dev, -ENOMEM,
 751                                      "could not allocate input device\n");
 752
 753         ts->client = client;
 754         ts->input = input_dev;
 755
 756         input_dev->name = "Neonode zForce touchscreen";
 757         input_dev->phys = ts->phys;
 758         input_dev->id.bustype = BUS_I2C;
 759
 760         input_dev->open = zforce_input_open;
 761         input_dev->close = zforce_input_close;
 762
 763         zforce_ts_parse_legacy_properties(ts);
 764         touchscreen_parse_properties(input_dev, true, &ts->prop);
 765         if (ts->prop.max_x == 0 || ts->prop.max_y == 0)
 766                 return dev_err_probe(&client->dev, -EINVAL, "no size specified");
 767
 768         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 769                              ZFORCE_MAX_AREA, 0, 0);
 770         input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
 771                              ZFORCE_MAX_AREA, 0, 0);
 772         input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
 773
 774         error = input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS,
 775                                   INPUT_MT_DIRECT);
 776         if (error)
 777                 return error;
 778
 779         input_set_drvdata(ts->input, ts);
 780
 781         init_completion(&ts->command_done);
 782
 783         /*
 784          * The zforce pulls the interrupt low when it has data ready.
 785          * After it is triggered the isr thread runs until all the available
 786          * packets have been read and the interrupt is high again.
 787          * Therefore we can trigger the interrupt anytime it is low and do
 788          * not need to limit it to the interrupt edge.
 789          */
 790         error = devm_request_threaded_irq(&client->dev, client->irq,
 791                                           zforce_irq, zforce_irq_thread,
 792                                           IRQF_ONESHOT, input_dev->name, ts);
 793         if (error)
 794                 return dev_err_probe(&client->dev, error,
 795                                      "irq %d request failed\n", client->irq);
 796
 797         i2c_set_clientdata(client, ts);
 798
 799         /* let the controller boot */
 800         gpiod_set_value_cansleep(ts->gpio_rst, 0);
 801
 802         ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
 803         if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
 804                 dev_warn(&client->dev, "bootcomplete timed out\n");
 805
 806         /* need to start device to get version information */
 807         error = zforce_command_wait(ts, COMMAND_INITIALIZE);
 808         if (error)
 809                 return dev_err_probe(&client->dev, error, "unable to initialize\n");
 810
 811         /* this gets the firmware version among other information */
 812         error = zforce_command_wait(ts, COMMAND_STATUS);
 813         if (error) {
 814                 dev_err_probe(&client->dev, error, "couldn't get status\n");
 815                 zforce_stop(ts);
 816                 return error;
 817         }
 818
 819         /* stop device and put it into sleep until it is opened */
 820         error = zforce_stop(ts);
 821         if (error)
 822                 return error;
 823
 824         device_set_wakeup_capable(&client->dev, true);
 825
 826         error = input_register_device(input_dev);
 827         if (error)
 828                 return dev_err_probe(&client->dev, error,
 829                                      "could not register input device\n");
 830
 831         return 0;
 832 }
 833
 834 static const struct i2c_device_id zforce_idtable[] = {
 835         { "zforce-ts" },
 836         { }
 837 };
 838 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
 839
 840 #ifdef CONFIG_OF
 841 static const struct of_device_id zforce_dt_idtable[] = {
 842         { .compatible = "neonode,zforce" },
 843         {},
 844 };
 845 MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
 846 #endif
 847
 848 static struct i2c_driver zforce_driver = {
 849         .driver = {
 850                 .name   = "zforce-ts",
 851                 .pm     = pm_sleep_ptr(&zforce_pm_ops),
 852                 .of_match_table = of_match_ptr(zforce_dt_idtable),
 853                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 854         },
 855         .probe          = zforce_probe,
 856         .id_table       = zforce_idtable,
 857 };
 858
 859 module_i2c_driver(zforce_driver);
 860
 861 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 862 MODULE_DESCRIPTION("zForce TouchScreen Driver");
 863 MODULE_LICENSE("GPL");