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/consumer.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/of.h>
  34
  35 #define WAIT_TIMEOUT            msecs_to_jiffies(1000)
  36
  37 #define FRAME_START             0xee
  38 #define FRAME_MAXSIZE           257
  39
  40 /* Offsets of the different parts of the payload the controller sends */
  41 #define PAYLOAD_HEADER          0
  42 #define PAYLOAD_LENGTH          1
  43 #define PAYLOAD_BODY            2
  44
  45 /* Response offsets */
  46 #define RESPONSE_ID             0
  47 #define RESPONSE_DATA           1
  48
  49 /* Commands */
  50 #define COMMAND_DEACTIVATE      0x00
  51 #define COMMAND_INITIALIZE      0x01
  52 #define COMMAND_RESOLUTION      0x02
  53 #define COMMAND_SETCONFIG       0x03
  54 #define COMMAND_DATAREQUEST     0x04
  55 #define COMMAND_SCANFREQ        0x08
  56 #define COMMAND_STATUS          0X1e
  57
  58 /*
  59  * Responses the controller sends as a result of
  60  * command requests
  61  */
  62 #define RESPONSE_DEACTIVATE     0x00
  63 #define RESPONSE_INITIALIZE     0x01
  64 #define RESPONSE_RESOLUTION     0x02
  65 #define RESPONSE_SETCONFIG      0x03
  66 #define RESPONSE_SCANFREQ       0x08
  67 #define RESPONSE_STATUS         0X1e
  68
  69 /*
  70  * Notifications are sent by the touch controller without
  71  * being requested by the driver and include for example
  72  * touch indications
  73  */
  74 #define NOTIFICATION_TOUCH              0x04
  75 #define NOTIFICATION_BOOTCOMPLETE       0x07
  76 #define NOTIFICATION_OVERRUN            0x25
  77 #define NOTIFICATION_PROXIMITY          0x26
  78 #define NOTIFICATION_INVALID_COMMAND    0xfe
  79
  80 #define ZFORCE_REPORT_POINTS            2
  81 #define ZFORCE_MAX_AREA                 0xff
  82
  83 #define STATE_DOWN                      0
  84 #define STATE_MOVE                      1
  85 #define STATE_UP                        2
  86
  87 #define SETCONFIG_DUALTOUCH             (1 << 0)
  88
  89 struct zforce_point {
  90         int coord_x;
  91         int coord_y;
  92         int state;
  93         int id;
  94         int area_major;
  95         int area_minor;
  96         int orientation;
  97         int pressure;
  98         int prblty;
  99 };
 100
 101 /*
 102  * @client              the i2c_client
 103  * @input               the input device
 104  * @suspending          in the process of going to suspend (don't emit wakeup
 105  *                      events for commands executed to suspend the device)
 106  * @suspended           device suspended
 107  * @access_mutex        serialize i2c-access, to keep multipart reads together
 108  * @command_done        completion to wait for the command result
 109  * @command_mutex       serialize commands sent to the ic
 110  * @command_waiting     the id of the command that is currently waiting
 111  *                      for a result
 112  * @command_result      returned result of the command
 113  */
 114 struct zforce_ts {
 115         struct i2c_client       *client;
 116         struct input_dev        *input;
 117         const struct zforce_ts_platdata *pdata;
 118         char                    phys[32];
 119
 120         struct regulator        *reg_vdd;
 121
 122         struct gpio_desc        *gpio_int;
 123         struct gpio_desc        *gpio_rst;
 124
 125         bool                    suspending;
 126         bool                    suspended;
 127         bool                    boot_complete;
 128
 129         /* Firmware version information */
 130         u16                     version_major;
 131         u16                     version_minor;
 132         u16                     version_build;
 133         u16                     version_rev;
 134
 135         struct mutex            access_mutex;
 136
 137         struct completion       command_done;
 138         struct mutex            command_mutex;
 139         int                     command_waiting;
 140         int                     command_result;
 141 };
 142
 143 static int zforce_command(struct zforce_ts *ts, u8 cmd)
 144 {
 145         struct i2c_client *client = ts->client;
 146         char buf[3];
 147         int ret;
 148
 149         dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
 150
 151         buf[0] = FRAME_START;
 152         buf[1] = 1; /* data size, command only */
 153         buf[2] = cmd;
 154
 155         mutex_lock(&ts->access_mutex);
 156         ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
 157         mutex_unlock(&ts->access_mutex);
 158         if (ret < 0) {
 159                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 160                 return ret;
 161         }
 162
 163         return 0;
 164 }
 165
 166 static void zforce_reset_assert(struct zforce_ts *ts)
 167 {
 168         gpiod_set_value_cansleep(ts->gpio_rst, 1);
 169 }
 170
 171 static void zforce_reset_deassert(struct zforce_ts *ts)
 172 {
 173         gpiod_set_value_cansleep(ts->gpio_rst, 0);
 174 }
 175
 176 static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
 177 {
 178         struct i2c_client *client = ts->client;
 179         int ret;
 180
 181         ret = mutex_trylock(&ts->command_mutex);
 182         if (!ret) {
 183                 dev_err(&client->dev, "already waiting for a command\n");
 184                 return -EBUSY;
 185         }
 186
 187         dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
 188                 buf[1], buf[2]);
 189
 190         ts->command_waiting = buf[2];
 191
 192         mutex_lock(&ts->access_mutex);
 193         ret = i2c_master_send(client, buf, len);
 194         mutex_unlock(&ts->access_mutex);
 195         if (ret < 0) {
 196                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 197                 goto unlock;
 198         }
 199
 200         dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
 201
 202         if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
 203                 ret = -ETIME;
 204                 goto unlock;
 205         }
 206
 207         ret = ts->command_result;
 208
 209 unlock:
 210         mutex_unlock(&ts->command_mutex);
 211         return ret;
 212 }
 213
 214 static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
 215 {
 216         struct i2c_client *client = ts->client;
 217         char buf[3];
 218         int ret;
 219
 220         dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
 221
 222         buf[0] = FRAME_START;
 223         buf[1] = 1; /* data size, command only */
 224         buf[2] = cmd;
 225
 226         ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 227         if (ret < 0) {
 228                 dev_err(&client->dev, "i2c send data request error: %d\n", ret);
 229                 return ret;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
 236 {
 237         struct i2c_client *client = ts->client;
 238         char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
 239                         (x & 0xff), ((x >> 8) & 0xff),
 240                         (y & 0xff), ((y >> 8) & 0xff) };
 241
 242         dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
 243
 244         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 245 }
 246
 247 static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
 248                                  u16 stylus)
 249 {
 250         struct i2c_client *client = ts->client;
 251         char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
 252                         (idle & 0xff), ((idle >> 8) & 0xff),
 253                         (finger & 0xff), ((finger >> 8) & 0xff),
 254                         (stylus & 0xff), ((stylus >> 8) & 0xff) };
 255
 256         dev_dbg(&client->dev,
 257                 "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
 258                 idle, finger, stylus);
 259
 260         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 261 }
 262
 263 static int zforce_setconfig(struct zforce_ts *ts, char b1)
 264 {
 265         struct i2c_client *client = ts->client;
 266         char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
 267                         b1, 0, 0, 0 };
 268
 269         dev_dbg(&client->dev, "set config to (%d)\n", b1);
 270
 271         return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
 272 }
 273
 274 static int zforce_start(struct zforce_ts *ts)
 275 {
 276         struct i2c_client *client = ts->client;
 277         const struct zforce_ts_platdata *pdata = ts->pdata;
 278         int ret;
 279
 280         dev_dbg(&client->dev, "starting device\n");
 281
 282         ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
 283         if (ret) {
 284                 dev_err(&client->dev, "Unable to initialize, %d\n", ret);
 285                 return ret;
 286         }
 287
 288         ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
 289         if (ret) {
 290                 dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
 291                 goto error;
 292         }
 293
 294         ret = zforce_scan_frequency(ts, 10, 50, 50);
 295         if (ret) {
 296                 dev_err(&client->dev, "Unable to set scan frequency, %d\n",
 297                         ret);
 298                 goto error;
 299         }
 300
 301         ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
 302         if (ret) {
 303                 dev_err(&client->dev, "Unable to set config\n");
 304                 goto error;
 305         }
 306
 307         /* start sending touch events */
 308         ret = zforce_command(ts, COMMAND_DATAREQUEST);
 309         if (ret) {
 310                 dev_err(&client->dev, "Unable to request data\n");
 311                 goto error;
 312         }
 313
 314         /*
 315          * Per NN, initial cal. take max. of 200msec.
 316          * Allow time to complete this calibration
 317          */
 318         msleep(200);
 319
 320         return 0;
 321
 322 error:
 323         zforce_command_wait(ts, COMMAND_DEACTIVATE);
 324         return ret;
 325 }
 326
 327 static int zforce_stop(struct zforce_ts *ts)
 328 {
 329         struct i2c_client *client = ts->client;
 330         int ret;
 331
 332         dev_dbg(&client->dev, "stopping device\n");
 333
 334         /* Deactivates touch sensing and puts the device into sleep. */
 335         ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
 336         if (ret != 0) {
 337                 dev_err(&client->dev, "could not deactivate device, %d\n",
 338                         ret);
 339                 return ret;
 340         }
 341
 342         return 0;
 343 }
 344
 345 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
 346 {
 347         struct i2c_client *client = ts->client;
 348         const struct zforce_ts_platdata *pdata = ts->pdata;
 349         struct zforce_point point;
 350         int count, i, num = 0;
 351
 352         count = payload[0];
 353         if (count > ZFORCE_REPORT_POINTS) {
 354                 dev_warn(&client->dev,
 355                          "too many coordinates %d, expected max %d\n",
 356                          count, ZFORCE_REPORT_POINTS);
 357                 count = ZFORCE_REPORT_POINTS;
 358         }
 359
 360         for (i = 0; i < count; i++) {
 361                 point.coord_x =
 362                         payload[9 * i + 2] << 8 | payload[9 * i + 1];
 363                 point.coord_y =
 364                         payload[9 * i + 4] << 8 | payload[9 * i + 3];
 365
 366                 if (point.coord_x > pdata->x_max ||
 367                     point.coord_y > pdata->y_max) {
 368                         dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
 369                                 point.coord_x, point.coord_y);
 370                         point.coord_x = point.coord_y = 0;
 371                 }
 372
 373                 point.state = payload[9 * i + 5] & 0x03;
 374                 point.id = (payload[9 * i + 5] & 0xfc) >> 2;
 375
 376                 /* determine touch major, minor and orientation */
 377                 point.area_major = max(payload[9 * i + 6],
 378                                           payload[9 * i + 7]);
 379                 point.area_minor = min(payload[9 * i + 6],
 380                                           payload[9 * i + 7]);
 381                 point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
 382
 383                 point.pressure = payload[9 * i + 8];
 384                 point.prblty = payload[9 * i + 9];
 385
 386                 dev_dbg(&client->dev,
 387                         "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
 388                         i, count, point.state, point.id,
 389                         point.pressure, point.prblty,
 390                         point.coord_x, point.coord_y,
 391                         point.area_major, point.area_minor,
 392                         point.orientation);
 393
 394                 /* the zforce id starts with "1", so needs to be decreased */
 395                 input_mt_slot(ts->input, point.id - 1);
 396
 397                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
 398                                                 point.state != STATE_UP);
 399
 400                 if (point.state != STATE_UP) {
 401                         input_report_abs(ts->input, ABS_MT_POSITION_X,
 402                                          point.coord_x);
 403                         input_report_abs(ts->input, ABS_MT_POSITION_Y,
 404                                          point.coord_y);
 405                         input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
 406                                          point.area_major);
 407                         input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
 408                                          point.area_minor);
 409                         input_report_abs(ts->input, ABS_MT_ORIENTATION,
 410                                          point.orientation);
 411                         num++;
 412                 }
 413         }
 414
 415         input_mt_sync_frame(ts->input);
 416
 417         input_mt_report_finger_count(ts->input, num);
 418
 419         input_sync(ts->input);
 420
 421         return 0;
 422 }
 423
 424 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
 425 {
 426         struct i2c_client *client = ts->client;
 427         int ret;
 428
 429         mutex_lock(&ts->access_mutex);
 430
 431         /* read 2 byte message header */
 432         ret = i2c_master_recv(client, buf, 2);
 433         if (ret < 0) {
 434                 dev_err(&client->dev, "error reading header: %d\n", ret);
 435                 goto unlock;
 436         }
 437
 438         if (buf[PAYLOAD_HEADER] != FRAME_START) {
 439                 dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
 440                 ret = -EIO;
 441                 goto unlock;
 442         }
 443
 444         if (buf[PAYLOAD_LENGTH] == 0) {
 445                 dev_err(&client->dev, "invalid payload length: %d\n",
 446                         buf[PAYLOAD_LENGTH]);
 447                 ret = -EIO;
 448                 goto unlock;
 449         }
 450
 451         /* read the message */
 452         ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
 453         if (ret < 0) {
 454                 dev_err(&client->dev, "error reading payload: %d\n", ret);
 455                 goto unlock;
 456         }
 457
 458         dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
 459                 buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
 460
 461 unlock:
 462         mutex_unlock(&ts->access_mutex);
 463         return ret;
 464 }
 465
 466 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
 467 {
 468         struct i2c_client *client = ts->client;
 469
 470         if (ts->command_waiting == cmd) {
 471                 dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
 472                 ts->command_result = result;
 473                 complete(&ts->command_done);
 474         } else {
 475                 dev_dbg(&client->dev, "command %d not for us\n", cmd);
 476         }
 477 }
 478
 479 static irqreturn_t zforce_irq(int irq, void *dev_id)
 480 {
 481         struct zforce_ts *ts = dev_id;
 482         struct i2c_client *client = ts->client;
 483
 484         if (ts->suspended && device_may_wakeup(&client->dev))
 485                 pm_wakeup_event(&client->dev, 500);
 486
 487         return IRQ_WAKE_THREAD;
 488 }
 489
 490 static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
 491 {
 492         struct zforce_ts *ts = dev_id;
 493         struct i2c_client *client = ts->client;
 494         int ret;
 495         u8 payload_buffer[FRAME_MAXSIZE];
 496         u8 *payload;
 497
 498         /*
 499          * When still suspended, return.
 500          * Due to the level-interrupt we will get re-triggered later.
 501          */
 502         if (ts->suspended) {
 503                 msleep(20);
 504                 return IRQ_HANDLED;
 505         }
 506
 507         dev_dbg(&client->dev, "handling interrupt\n");
 508
 509         /* Don't emit wakeup events from commands run by zforce_suspend */
 510         if (!ts->suspending && device_may_wakeup(&client->dev))
 511                 pm_stay_awake(&client->dev);
 512
 513         /*
 514          * Run at least once and exit the loop if
 515          * - the optional interrupt GPIO isn't specified
 516          *   (there is only one packet read per ISR invocation, then)
 517          * or
 518          * - the GPIO isn't active any more
 519          *   (packet read until the level GPIO indicates that there is
 520          *    no IRQ any more)
 521          */
 522         do {
 523                 ret = zforce_read_packet(ts, payload_buffer);
 524                 if (ret < 0) {
 525                         dev_err(&client->dev,
 526                                 "could not read packet, ret: %d\n", ret);
 527                         break;
 528                 }
 529
 530                 payload =  &payload_buffer[PAYLOAD_BODY];
 531
 532                 switch (payload[RESPONSE_ID]) {
 533                 case NOTIFICATION_TOUCH:
 534                         /*
 535                          * Always report touch-events received while
 536                          * suspending, when being a wakeup source
 537                          */
 538                         if (ts->suspending && device_may_wakeup(&client->dev))
 539                                 pm_wakeup_event(&client->dev, 500);
 540                         zforce_touch_event(ts, &payload[RESPONSE_DATA]);
 541                         break;
 542
 543                 case NOTIFICATION_BOOTCOMPLETE:
 544                         ts->boot_complete = payload[RESPONSE_DATA];
 545                         zforce_complete(ts, payload[RESPONSE_ID], 0);
 546                         break;
 547
 548                 case RESPONSE_INITIALIZE:
 549                 case RESPONSE_DEACTIVATE:
 550                 case RESPONSE_SETCONFIG:
 551                 case RESPONSE_RESOLUTION:
 552                 case RESPONSE_SCANFREQ:
 553                         zforce_complete(ts, payload[RESPONSE_ID],
 554                                         payload[RESPONSE_DATA]);
 555                         break;
 556
 557                 case RESPONSE_STATUS:
 558                         /*
 559                          * Version Payload Results
 560                          * [2:major] [2:minor] [2:build] [2:rev]
 561                          */
 562                         ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
 563                                                 payload[RESPONSE_DATA];
 564                         ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
 565                                                 payload[RESPONSE_DATA + 2];
 566                         ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
 567                                                 payload[RESPONSE_DATA + 4];
 568                         ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
 569                                                 payload[RESPONSE_DATA + 6];
 570                         dev_dbg(&ts->client->dev,
 571                                 "Firmware Version %04x:%04x %04x:%04x\n",
 572                                 ts->version_major, ts->version_minor,
 573                                 ts->version_build, ts->version_rev);
 574
 575                         zforce_complete(ts, payload[RESPONSE_ID], 0);
 576                         break;
 577
 578                 case NOTIFICATION_INVALID_COMMAND:
 579                         dev_err(&ts->client->dev, "invalid command: 0x%x\n",
 580                                 payload[RESPONSE_DATA]);
 581                         break;
 582
 583                 default:
 584                         dev_err(&ts->client->dev,
 585                                 "unrecognized response id: 0x%x\n",
 586                                 payload[RESPONSE_ID]);
 587                         break;
 588                 }
 589         } while (gpiod_get_value_cansleep(ts->gpio_int));
 590
 591         if (!ts->suspending && device_may_wakeup(&client->dev))
 592                 pm_relax(&client->dev);
 593
 594         dev_dbg(&client->dev, "finished interrupt\n");
 595
 596         return IRQ_HANDLED;
 597 }
 598
 599 static int zforce_input_open(struct input_dev *dev)
 600 {
 601         struct zforce_ts *ts = input_get_drvdata(dev);
 602
 603         return zforce_start(ts);
 604 }
 605
 606 static void zforce_input_close(struct input_dev *dev)
 607 {
 608         struct zforce_ts *ts = input_get_drvdata(dev);
 609         struct i2c_client *client = ts->client;
 610         int ret;
 611
 612         ret = zforce_stop(ts);
 613         if (ret)
 614                 dev_warn(&client->dev, "stopping zforce failed\n");
 615
 616         return;
 617 }
 618
 619 static int __maybe_unused zforce_suspend(struct device *dev)
 620 {
 621         struct i2c_client *client = to_i2c_client(dev);
 622         struct zforce_ts *ts = i2c_get_clientdata(client);
 623         struct input_dev *input = ts->input;
 624         int ret = 0;
 625
 626         mutex_lock(&input->mutex);
 627         ts->suspending = true;
 628
 629         /*
 630          * When configured as a wakeup source device should always wake
 631          * the system, therefore start device if necessary.
 632          */
 633         if (device_may_wakeup(&client->dev)) {
 634                 dev_dbg(&client->dev, "suspend while being a wakeup source\n");
 635
 636                 /* Need to start device, if not open, to be a wakeup source. */
 637                 if (!input->users) {
 638                         ret = zforce_start(ts);
 639                         if (ret)
 640                                 goto unlock;
 641                 }
 642
 643                 enable_irq_wake(client->irq);
 644         } else if (input->users) {
 645                 dev_dbg(&client->dev,
 646                         "suspend without being a wakeup source\n");
 647
 648                 ret = zforce_stop(ts);
 649                 if (ret)
 650                         goto unlock;
 651
 652                 disable_irq(client->irq);
 653         }
 654
 655         ts->suspended = true;
 656
 657 unlock:
 658         ts->suspending = false;
 659         mutex_unlock(&input->mutex);
 660
 661         return ret;
 662 }
 663
 664 static int __maybe_unused zforce_resume(struct device *dev)
 665 {
 666         struct i2c_client *client = to_i2c_client(dev);
 667         struct zforce_ts *ts = i2c_get_clientdata(client);
 668         struct input_dev *input = ts->input;
 669         int ret = 0;
 670
 671         mutex_lock(&input->mutex);
 672
 673         ts->suspended = false;
 674
 675         if (device_may_wakeup(&client->dev)) {
 676                 dev_dbg(&client->dev, "resume from being a wakeup source\n");
 677
 678                 disable_irq_wake(client->irq);
 679
 680                 /* need to stop device if it was not open on suspend */
 681                 if (!input->users) {
 682                         ret = zforce_stop(ts);
 683                         if (ret)
 684                                 goto unlock;
 685                 }
 686         } else if (input->users) {
 687                 dev_dbg(&client->dev, "resume without being a wakeup source\n");
 688
 689                 enable_irq(client->irq);
 690
 691                 ret = zforce_start(ts);
 692                 if (ret < 0)
 693                         goto unlock;
 694         }
 695
 696 unlock:
 697         mutex_unlock(&input->mutex);
 698
 699         return ret;
 700 }
 701
 702 static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
 703
 704 static void zforce_reset(void *data)
 705 {
 706         struct zforce_ts *ts = data;
 707
 708         zforce_reset_assert(ts);
 709
 710         udelay(10);
 711
 712         if (!IS_ERR(ts->reg_vdd))
 713                 regulator_disable(ts->reg_vdd);
 714 }
 715
 716 static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
 717 {
 718         struct zforce_ts_platdata *pdata;
 719         struct device_node *np = dev->of_node;
 720
 721         if (!np)
 722                 return ERR_PTR(-ENOENT);
 723
 724         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 725         if (!pdata) {
 726                 dev_err(dev, "failed to allocate platform data\n");
 727                 return ERR_PTR(-ENOMEM);
 728         }
 729
 730         if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
 731                 dev_err(dev, "failed to get x-size property\n");
 732                 return ERR_PTR(-EINVAL);
 733         }
 734
 735         if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
 736                 dev_err(dev, "failed to get y-size property\n");
 737                 return ERR_PTR(-EINVAL);
 738         }
 739
 740         return pdata;
 741 }
 742
 743 static int zforce_probe(struct i2c_client *client,
 744                         const struct i2c_device_id *id)
 745 {
 746         const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
 747         struct zforce_ts *ts;
 748         struct input_dev *input_dev;
 749         int ret;
 750
 751         if (!pdata) {
 752                 pdata = zforce_parse_dt(&client->dev);
 753                 if (IS_ERR(pdata))
 754                         return PTR_ERR(pdata);
 755         }
 756
 757         ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
 758         if (!ts)
 759                 return -ENOMEM;
 760
 761         ts->gpio_rst = devm_gpiod_get_optional(&client->dev, "reset",
 762                                                GPIOD_OUT_HIGH);
 763         if (IS_ERR(ts->gpio_rst)) {
 764                 ret = PTR_ERR(ts->gpio_rst);
 765                 dev_err(&client->dev,
 766                         "failed to request reset GPIO: %d\n", ret);
 767                 return ret;
 768         }
 769
 770         if (ts->gpio_rst) {
 771                 ts->gpio_int = devm_gpiod_get_optional(&client->dev, "irq",
 772                                                        GPIOD_IN);
 773                 if (IS_ERR(ts->gpio_int)) {
 774                         ret = PTR_ERR(ts->gpio_int);
 775                         dev_err(&client->dev,
 776                                 "failed to request interrupt GPIO: %d\n", ret);
 777                         return ret;
 778                 }
 779         } else {
 780                 /*
 781                  * Deprecated GPIO handling for compatibility
 782                  * with legacy binding.
 783                  */
 784
 785                 /* INT GPIO */
 786                 ts->gpio_int = devm_gpiod_get_index(&client->dev, NULL, 0,
 787                                                     GPIOD_IN);
 788                 if (IS_ERR(ts->gpio_int)) {
 789                         ret = PTR_ERR(ts->gpio_int);
 790                         dev_err(&client->dev,
 791                                 "failed to request interrupt GPIO: %d\n", ret);
 792                         return ret;
 793                 }
 794
 795                 /* RST GPIO */
 796                 ts->gpio_rst = devm_gpiod_get_index(&client->dev, NULL, 1,
 797                                             GPIOD_OUT_HIGH);
 798                 if (IS_ERR(ts->gpio_rst)) {
 799                         ret = PTR_ERR(ts->gpio_rst);
 800                         dev_err(&client->dev,
 801                                 "failed to request reset GPIO: %d\n", ret);
 802                         return ret;
 803                 }
 804         }
 805
 806         ts->reg_vdd = devm_regulator_get_optional(&client->dev, "vdd");
 807         if (IS_ERR(ts->reg_vdd)) {
 808                 ret = PTR_ERR(ts->reg_vdd);
 809                 if (ret == -EPROBE_DEFER)
 810                         return ret;
 811         } else {
 812                 ret = regulator_enable(ts->reg_vdd);
 813                 if (ret)
 814                         return ret;
 815
 816                 /*
 817                  * according to datasheet add 100us grace time after regular
 818                  * regulator enable delay.
 819                  */
 820                 udelay(100);
 821         }
 822
 823         ret = devm_add_action(&client->dev, zforce_reset, ts);
 824         if (ret) {
 825                 dev_err(&client->dev, "failed to register reset action, %d\n",
 826                         ret);
 827
 828                 /* hereafter the regulator will be disabled by the action */
 829                 if (!IS_ERR(ts->reg_vdd))
 830                         regulator_disable(ts->reg_vdd);
 831
 832                 return ret;
 833         }
 834
 835         snprintf(ts->phys, sizeof(ts->phys),
 836                  "%s/input0", dev_name(&client->dev));
 837
 838         input_dev = devm_input_allocate_device(&client->dev);
 839         if (!input_dev) {
 840                 dev_err(&client->dev, "could not allocate input device\n");
 841                 return -ENOMEM;
 842         }
 843
 844         mutex_init(&ts->access_mutex);
 845         mutex_init(&ts->command_mutex);
 846
 847         ts->pdata = pdata;
 848         ts->client = client;
 849         ts->input = input_dev;
 850
 851         input_dev->name = "Neonode zForce touchscreen";
 852         input_dev->phys = ts->phys;
 853         input_dev->id.bustype = BUS_I2C;
 854
 855         input_dev->open = zforce_input_open;
 856         input_dev->close = zforce_input_close;
 857
 858         __set_bit(EV_KEY, input_dev->evbit);
 859         __set_bit(EV_SYN, input_dev->evbit);
 860         __set_bit(EV_ABS, input_dev->evbit);
 861
 862         /* For multi touch */
 863         input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
 864                              pdata->x_max, 0, 0);
 865         input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
 866                              pdata->y_max, 0, 0);
 867
 868         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 869                              ZFORCE_MAX_AREA, 0, 0);
 870         input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
 871                              ZFORCE_MAX_AREA, 0, 0);
 872         input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
 873         input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
 874
 875         input_set_drvdata(ts->input, ts);
 876
 877         init_completion(&ts->command_done);
 878
 879         /*
 880          * The zforce pulls the interrupt low when it has data ready.
 881          * After it is triggered the isr thread runs until all the available
 882          * packets have been read and the interrupt is high again.
 883          * Therefore we can trigger the interrupt anytime it is low and do
 884          * not need to limit it to the interrupt edge.
 885          */
 886         ret = devm_request_threaded_irq(&client->dev, client->irq,
 887                                         zforce_irq, zforce_irq_thread,
 888                                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 889                                         input_dev->name, ts);
 890         if (ret) {
 891                 dev_err(&client->dev, "irq %d request failed\n", client->irq);
 892                 return ret;
 893         }
 894
 895         i2c_set_clientdata(client, ts);
 896
 897         /* let the controller boot */
 898         zforce_reset_deassert(ts);
 899
 900         ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
 901         if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
 902                 dev_warn(&client->dev, "bootcomplete timed out\n");
 903
 904         /* need to start device to get version information */
 905         ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
 906         if (ret) {
 907                 dev_err(&client->dev, "unable to initialize, %d\n", ret);
 908                 return ret;
 909         }
 910
 911         /* this gets the firmware version among other information */
 912         ret = zforce_command_wait(ts, COMMAND_STATUS);
 913         if (ret < 0) {
 914                 dev_err(&client->dev, "couldn't get status, %d\n", ret);
 915                 zforce_stop(ts);
 916                 return ret;
 917         }
 918
 919         /* stop device and put it into sleep until it is opened */
 920         ret = zforce_stop(ts);
 921         if (ret < 0)
 922                 return ret;
 923
 924         device_set_wakeup_capable(&client->dev, true);
 925
 926         ret = input_register_device(input_dev);
 927         if (ret) {
 928                 dev_err(&client->dev, "could not register input device, %d\n",
 929                         ret);
 930                 return ret;
 931         }
 932
 933         return 0;
 934 }
 935
 936 static struct i2c_device_id zforce_idtable[] = {
 937         { "zforce-ts", 0 },
 938         { }
 939 };
 940 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
 941
 942 #ifdef CONFIG_OF
 943 static const struct of_device_id zforce_dt_idtable[] = {
 944         { .compatible = "neonode,zforce" },
 945         {},
 946 };
 947 MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
 948 #endif
 949
 950 static struct i2c_driver zforce_driver = {
 951         .driver = {
 952                 .name   = "zforce-ts",
 953                 .pm     = &zforce_pm_ops,
 954                 .of_match_table = of_match_ptr(zforce_dt_idtable),
 955         },
 956         .probe          = zforce_probe,
 957         .id_table       = zforce_idtable,
 958 };
 959
 960 module_i2c_driver(zforce_driver);
 961
 962 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 963 MODULE_DESCRIPTION("zForce TouchScreen Driver");
 964 MODULE_LICENSE("GPL");