drivers/input/touchscreen/cyttsp_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Core Source for:
   4  * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
   5  * For use with Cypress Txx3xx parts.
   6  * Supported parts include:
   7  * CY8CTST341
   8  * CY8CTMA340
   9  *
  10  * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
  11  * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
  12  *
  13  * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
  14  */
  15
  16 #include <linux/delay.h>
  17 #include <linux/input.h>
  18 #include <linux/input/mt.h>
  19 #include <linux/input/touchscreen.h>
  20 #include <linux/gpio.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/slab.h>
  23 #include <linux/property.h>
  24 #include <linux/gpio/consumer.h>
  25
  26 #include "cyttsp_core.h"
  27
  28 /* Bootloader number of command keys */
  29 #define CY_NUM_BL_KEYS          8
  30
  31 /* helpers */
  32 #define GET_NUM_TOUCHES(x)              ((x) & 0x0F)
  33 #define IS_LARGE_AREA(x)                (((x) & 0x10) >> 4)
  34 #define IS_BAD_PKT(x)                   ((x) & 0x20)
  35 #define IS_VALID_APP(x)                 ((x) & 0x01)
  36 #define IS_OPERATIONAL_ERR(x)           ((x) & 0x3F)
  37 #define GET_HSTMODE(reg)                (((reg) & 0x70) >> 4)
  38 #define GET_BOOTLOADERMODE(reg)         (((reg) & 0x10) >> 4)
  39
  40 #define CY_REG_BASE                     0x00
  41 #define CY_REG_ACT_DIST                 0x1E
  42 #define CY_REG_ACT_INTRVL               0x1D
  43 #define CY_REG_TCH_TMOUT                (CY_REG_ACT_INTRVL + 1)
  44 #define CY_REG_LP_INTRVL                (CY_REG_TCH_TMOUT + 1)
  45 #define CY_MAXZ                         255
  46 #define CY_DELAY_DFLT                   20 /* ms */
  47 #define CY_DELAY_MAX                    500
  48 #define CY_ACT_DIST_DFLT                0xF8
  49 #define CY_ACT_DIST_MASK                0x0F
  50 #define CY_HNDSHK_BIT                   0x80
  51 /* device mode bits */
  52 #define CY_OPERATE_MODE                 0x00
  53 #define CY_SYSINFO_MODE                 0x10
  54 /* power mode select bits */
  55 #define CY_SOFT_RESET_MODE              0x01 /* return to Bootloader mode */
  56 #define CY_DEEP_SLEEP_MODE              0x02
  57 #define CY_LOW_POWER_MODE               0x04
  58
  59 /* Slots management */
  60 #define CY_MAX_FINGER                   4
  61 #define CY_MAX_ID                       16
  62
  63 static const u8 bl_command[] = {
  64         0x00,                   /* file offset */
  65         0xFF,                   /* command */
  66         0xA5,                   /* exit bootloader command */
  67         0, 1, 2, 3, 4, 5, 6, 7  /* default keys */
  68 };
  69
  70 static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
  71                                 u8 length, void *buf)
  72 {
  73         int error;
  74         int tries;
  75
  76         for (tries = 0; tries < CY_NUM_RETRY; tries++) {
  77                 error = ts->bus_ops->read(ts->dev, ts->xfer_buf, command,
  78                                 length, buf);
  79                 if (!error)
  80                         return 0;
  81
  82                 msleep(CY_DELAY_DFLT);
  83         }
  84
  85         return -EIO;
  86 }
  87
  88 static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
  89                                  u8 length, void *buf)
  90 {
  91         int error;
  92         int tries;
  93
  94         for (tries = 0; tries < CY_NUM_RETRY; tries++) {
  95                 error = ts->bus_ops->write(ts->dev, ts->xfer_buf, command,
  96                                 length, buf);
  97                 if (!error)
  98                         return 0;
  99
 100                 msleep(CY_DELAY_DFLT);
 101         }
 102
 103         return -EIO;
 104 }
 105
 106 static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
 107 {
 108         return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
 109 }
 110
 111 static int cyttsp_handshake(struct cyttsp *ts)
 112 {
 113         if (ts->use_hndshk)
 114                 return ttsp_send_command(ts,
 115                                 ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
 116
 117         return 0;
 118 }
 119
 120 static int cyttsp_load_bl_regs(struct cyttsp *ts)
 121 {
 122         memset(&ts->bl_data, 0, sizeof(ts->bl_data));
 123         ts->bl_data.bl_status = 0x10;
 124
 125         return ttsp_read_block_data(ts, CY_REG_BASE,
 126                                     sizeof(ts->bl_data), &ts->bl_data);
 127 }
 128
 129 static int cyttsp_exit_bl_mode(struct cyttsp *ts)
 130 {
 131         int error;
 132         u8 bl_cmd[sizeof(bl_command)];
 133
 134         memcpy(bl_cmd, bl_command, sizeof(bl_command));
 135         if (ts->bl_keys)
 136                 memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
 137                         ts->bl_keys, CY_NUM_BL_KEYS);
 138
 139         error = ttsp_write_block_data(ts, CY_REG_BASE,
 140                                       sizeof(bl_cmd), bl_cmd);
 141         if (error)
 142                 return error;
 143
 144         /* wait for TTSP Device to complete the operation */
 145         msleep(CY_DELAY_DFLT);
 146
 147         error = cyttsp_load_bl_regs(ts);
 148         if (error)
 149                 return error;
 150
 151         if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
 152                 return -EIO;
 153
 154         return 0;
 155 }
 156
 157 static int cyttsp_set_operational_mode(struct cyttsp *ts)
 158 {
 159         int error;
 160
 161         error = ttsp_send_command(ts, CY_OPERATE_MODE);
 162         if (error)
 163                 return error;
 164
 165         /* wait for TTSP Device to complete switch to Operational mode */
 166         error = ttsp_read_block_data(ts, CY_REG_BASE,
 167                                      sizeof(ts->xy_data), &ts->xy_data);
 168         if (error)
 169                 return error;
 170
 171         error = cyttsp_handshake(ts);
 172         if (error)
 173                 return error;
 174
 175         return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
 176 }
 177
 178 static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
 179 {
 180         int error;
 181
 182         memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));
 183
 184         /* switch to sysinfo mode */
 185         error = ttsp_send_command(ts, CY_SYSINFO_MODE);
 186         if (error)
 187                 return error;
 188
 189         /* read sysinfo registers */
 190         msleep(CY_DELAY_DFLT);
 191         error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
 192                                       &ts->sysinfo_data);
 193         if (error)
 194                 return error;
 195
 196         error = cyttsp_handshake(ts);
 197         if (error)
 198                 return error;
 199
 200         if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
 201                 return -EIO;
 202
 203         return 0;
 204 }
 205
 206 static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
 207 {
 208         int retval = 0;
 209
 210         if (ts->act_intrvl != CY_ACT_INTRVL_DFLT ||
 211             ts->tch_tmout != CY_TCH_TMOUT_DFLT ||
 212             ts->lp_intrvl != CY_LP_INTRVL_DFLT) {
 213
 214                 u8 intrvl_ray[] = {
 215                         ts->act_intrvl,
 216                         ts->tch_tmout,
 217                         ts->lp_intrvl
 218                 };
 219
 220                 /* set intrvl registers */
 221                 retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
 222                                         sizeof(intrvl_ray), intrvl_ray);
 223                 msleep(CY_DELAY_DFLT);
 224         }
 225
 226         return retval;
 227 }
 228
 229 static void cyttsp_hard_reset(struct cyttsp *ts)
 230 {
 231         if (ts->reset_gpio) {
 232                 gpiod_set_value_cansleep(ts->reset_gpio, 1);
 233                 msleep(CY_DELAY_DFLT);
 234                 gpiod_set_value_cansleep(ts->reset_gpio, 0);
 235                 msleep(CY_DELAY_DFLT);
 236         }
 237 }
 238
 239 static int cyttsp_soft_reset(struct cyttsp *ts)
 240 {
 241         unsigned long timeout;
 242         int retval;
 243
 244         /* wait for interrupt to set ready completion */
 245         reinit_completion(&ts->bl_ready);
 246         ts->state = CY_BL_STATE;
 247
 248         enable_irq(ts->irq);
 249
 250         retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
 251         if (retval)
 252                 goto out;
 253
 254         timeout = wait_for_completion_timeout(&ts->bl_ready,
 255                         msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
 256         retval = timeout ? 0 : -EIO;
 257
 258 out:
 259         ts->state = CY_IDLE_STATE;
 260         disable_irq(ts->irq);
 261         return retval;
 262 }
 263
 264 static int cyttsp_act_dist_setup(struct cyttsp *ts)
 265 {
 266         u8 act_dist_setup = ts->act_dist;
 267
 268         /* Init gesture; active distance setup */
 269         return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
 270                                 sizeof(act_dist_setup), &act_dist_setup);
 271 }
 272
 273 static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
 274 {
 275         ids[0] = xy_data->touch12_id >> 4;
 276         ids[1] = xy_data->touch12_id & 0xF;
 277         ids[2] = xy_data->touch34_id >> 4;
 278         ids[3] = xy_data->touch34_id & 0xF;
 279 }
 280
 281 static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
 282                                                int idx)
 283 {
 284         switch (idx) {
 285         case 0:
 286                 return &xy_data->tch1;
 287         case 1:
 288                 return &xy_data->tch2;
 289         case 2:
 290                 return &xy_data->tch3;
 291         case 3:
 292                 return &xy_data->tch4;
 293         default:
 294                 return NULL;
 295         }
 296 }
 297
 298 static void cyttsp_report_tchdata(struct cyttsp *ts)
 299 {
 300         struct cyttsp_xydata *xy_data = &ts->xy_data;
 301         struct input_dev *input = ts->input;
 302         int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
 303         const struct cyttsp_tch *tch;
 304         int ids[CY_MAX_ID];
 305         int i;
 306         DECLARE_BITMAP(used, CY_MAX_ID);
 307
 308         if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
 309                 /* terminate all active tracks */
 310                 num_tch = 0;
 311                 dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
 312         } else if (num_tch > CY_MAX_FINGER) {
 313                 /* terminate all active tracks */
 314                 num_tch = 0;
 315                 dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
 316         } else if (IS_BAD_PKT(xy_data->tt_mode)) {
 317                 /* terminate all active tracks */
 318                 num_tch = 0;
 319                 dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
 320         }
 321
 322         cyttsp_extract_track_ids(xy_data, ids);
 323
 324         bitmap_zero(used, CY_MAX_ID);
 325
 326         for (i = 0; i < num_tch; i++) {
 327                 tch = cyttsp_get_tch(xy_data, i);
 328
 329                 input_mt_slot(input, ids[i]);
 330                 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 331                 input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
 332                 input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
 333                 input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
 334
 335                 __set_bit(ids[i], used);
 336         }
 337
 338         for (i = 0; i < CY_MAX_ID; i++) {
 339                 if (test_bit(i, used))
 340                         continue;
 341
 342                 input_mt_slot(input, i);
 343                 input_mt_report_slot_inactive(input);
 344         }
 345
 346         input_sync(input);
 347 }
 348
 349 static irqreturn_t cyttsp_irq(int irq, void *handle)
 350 {
 351         struct cyttsp *ts = handle;
 352         int error;
 353
 354         if (unlikely(ts->state == CY_BL_STATE)) {
 355                 complete(&ts->bl_ready);
 356                 goto out;
 357         }
 358
 359         /* Get touch data from CYTTSP device */
 360         error = ttsp_read_block_data(ts, CY_REG_BASE,
 361                                  sizeof(struct cyttsp_xydata), &ts->xy_data);
 362         if (error)
 363                 goto out;
 364
 365         /* provide flow control handshake */
 366         error = cyttsp_handshake(ts);
 367         if (error)
 368                 goto out;
 369
 370         if (unlikely(ts->state == CY_IDLE_STATE))
 371                 goto out;
 372
 373         if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
 374                 /*
 375                  * TTSP device has reset back to bootloader mode.
 376                  * Restore to operational mode.
 377                  */
 378                 error = cyttsp_exit_bl_mode(ts);
 379                 if (error) {
 380                         dev_err(ts->dev,
 381                                 "Could not return to operational mode, err: %d\n",
 382                                 error);
 383                         ts->state = CY_IDLE_STATE;
 384                 }
 385         } else {
 386                 cyttsp_report_tchdata(ts);
 387         }
 388
 389 out:
 390         return IRQ_HANDLED;
 391 }
 392
 393 static int cyttsp_power_on(struct cyttsp *ts)
 394 {
 395         int error;
 396
 397         error = cyttsp_soft_reset(ts);
 398         if (error)
 399                 return error;
 400
 401         error = cyttsp_load_bl_regs(ts);
 402         if (error)
 403                 return error;
 404
 405         if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
 406             IS_VALID_APP(ts->bl_data.bl_status)) {
 407                 error = cyttsp_exit_bl_mode(ts);
 408                 if (error)
 409                         return error;
 410         }
 411
 412         if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
 413             IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
 414                 return -ENODEV;
 415         }
 416
 417         error = cyttsp_set_sysinfo_mode(ts);
 418         if (error)
 419                 return error;
 420
 421         error = cyttsp_set_sysinfo_regs(ts);
 422         if (error)
 423                 return error;
 424
 425         error = cyttsp_set_operational_mode(ts);
 426         if (error)
 427                 return error;
 428
 429         /* init active distance */
 430         error = cyttsp_act_dist_setup(ts);
 431         if (error)
 432                 return error;
 433
 434         ts->state = CY_ACTIVE_STATE;
 435
 436         return 0;
 437 }
 438
 439 static int cyttsp_enable(struct cyttsp *ts)
 440 {
 441         int error;
 442
 443         /*
 444          * The device firmware can wake on an I2C or SPI memory slave
 445          * address match. So just reading a register is sufficient to
 446          * wake up the device. The first read attempt will fail but it
 447          * will wake it up making the second read attempt successful.
 448          */
 449         error = ttsp_read_block_data(ts, CY_REG_BASE,
 450                                      sizeof(ts->xy_data), &ts->xy_data);
 451         if (error)
 452                 return error;
 453
 454         if (GET_HSTMODE(ts->xy_data.hst_mode))
 455                 return -EIO;
 456
 457         enable_irq(ts->irq);
 458
 459         return 0;
 460 }
 461
 462 static int cyttsp_disable(struct cyttsp *ts)
 463 {
 464         int error;
 465
 466         error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
 467         if (error)
 468                 return error;
 469
 470         disable_irq(ts->irq);
 471
 472         return 0;
 473 }
 474
 475 static int __maybe_unused cyttsp_suspend(struct device *dev)
 476 {
 477         struct cyttsp *ts = dev_get_drvdata(dev);
 478         int retval = 0;
 479
 480         mutex_lock(&ts->input->mutex);
 481
 482         if (input_device_enabled(ts->input)) {
 483                 retval = cyttsp_disable(ts);
 484                 if (retval == 0)
 485                         ts->suspended = true;
 486         }
 487
 488         mutex_unlock(&ts->input->mutex);
 489
 490         return retval;
 491 }
 492
 493 static int __maybe_unused cyttsp_resume(struct device *dev)
 494 {
 495         struct cyttsp *ts = dev_get_drvdata(dev);
 496
 497         mutex_lock(&ts->input->mutex);
 498
 499         if (input_device_enabled(ts->input))
 500                 cyttsp_enable(ts);
 501
 502         ts->suspended = false;
 503
 504         mutex_unlock(&ts->input->mutex);
 505
 506         return 0;
 507 }
 508
 509 SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
 510 EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
 511
 512 static int cyttsp_open(struct input_dev *dev)
 513 {
 514         struct cyttsp *ts = input_get_drvdata(dev);
 515         int retval = 0;
 516
 517         if (!ts->suspended)
 518                 retval = cyttsp_enable(ts);
 519
 520         return retval;
 521 }
 522
 523 static void cyttsp_close(struct input_dev *dev)
 524 {
 525         struct cyttsp *ts = input_get_drvdata(dev);
 526
 527         if (!ts->suspended)
 528                 cyttsp_disable(ts);
 529 }
 530
 531 static int cyttsp_parse_properties(struct cyttsp *ts)
 532 {
 533         struct device *dev = ts->dev;
 534         u32 dt_value;
 535         int ret;
 536
 537         ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
 538         if (!ts->bl_keys)
 539                 return -ENOMEM;
 540
 541         /* Set some default values */
 542         ts->use_hndshk = false;
 543         ts->act_dist = CY_ACT_DIST_DFLT;
 544         ts->act_intrvl = CY_ACT_INTRVL_DFLT;
 545         ts->tch_tmout = CY_TCH_TMOUT_DFLT;
 546         ts->lp_intrvl = CY_LP_INTRVL_DFLT;
 547
 548         ret = device_property_read_u8_array(dev, "bootloader-key",
 549                                             ts->bl_keys, CY_NUM_BL_KEYS);
 550         if (ret) {
 551                 dev_err(dev,
 552                         "bootloader-key property could not be retrieved\n");
 553                 return ret;
 554         }
 555
 556         ts->use_hndshk = device_property_present(dev, "use-handshake");
 557
 558         if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
 559                 if (dt_value > 15) {
 560                         dev_err(dev, "active-distance (%u) must be [0-15]\n",
 561                                 dt_value);
 562                         return -EINVAL;
 563                 }
 564                 ts->act_dist &= ~CY_ACT_DIST_MASK;
 565                 ts->act_dist |= dt_value;
 566         }
 567
 568         if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
 569                 if (dt_value > 255) {
 570                         dev_err(dev, "active-interval-ms (%u) must be [0-255]\n",
 571                                 dt_value);
 572                         return -EINVAL;
 573                 }
 574                 ts->act_intrvl = dt_value;
 575         }
 576
 577         if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
 578                 if (dt_value > 2550) {
 579                         dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]\n",
 580                                 dt_value);
 581                         return -EINVAL;
 582                 }
 583                 /* Register value is expressed in 0.01s / bit */
 584                 ts->lp_intrvl = dt_value / 10;
 585         }
 586
 587         if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
 588                 if (dt_value > 2550) {
 589                         dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]\n",
 590                                 dt_value);
 591                         return -EINVAL;
 592                 }
 593                 /* Register value is expressed in 0.01s / bit */
 594                 ts->tch_tmout = dt_value / 10;
 595         }
 596
 597         return 0;
 598 }
 599
 600 struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
 601                             struct device *dev, int irq, size_t xfer_buf_size)
 602 {
 603         struct cyttsp *ts;
 604         struct input_dev *input_dev;
 605         int error;
 606
 607         ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
 608         if (!ts)
 609                 return ERR_PTR(-ENOMEM);
 610
 611         input_dev = devm_input_allocate_device(dev);
 612         if (!input_dev)
 613                 return ERR_PTR(-ENOMEM);
 614
 615         ts->dev = dev;
 616         ts->input = input_dev;
 617         ts->bus_ops = bus_ops;
 618         ts->irq = irq;
 619
 620         ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
 621         if (IS_ERR(ts->reset_gpio)) {
 622                 error = PTR_ERR(ts->reset_gpio);
 623                 dev_err(dev, "Failed to request reset gpio, error %d\n", error);
 624                 return ERR_PTR(error);
 625         }
 626
 627         error = cyttsp_parse_properties(ts);
 628         if (error)
 629                 return ERR_PTR(error);
 630
 631         init_completion(&ts->bl_ready);
 632         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
 633
 634         input_dev->name = "Cypress TTSP TouchScreen";
 635         input_dev->phys = ts->phys;
 636         input_dev->id.bustype = bus_ops->bustype;
 637         input_dev->dev.parent = ts->dev;
 638
 639         input_dev->open = cyttsp_open;
 640         input_dev->close = cyttsp_close;
 641
 642         input_set_drvdata(input_dev, ts);
 643
 644         input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
 645         input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
 646         touchscreen_parse_properties(input_dev, true, NULL);
 647
 648         error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
 649         if (error) {
 650                 dev_err(dev, "Unable to init MT slots.\n");
 651                 return ERR_PTR(error);
 652         }
 653
 654         error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
 655                                           IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 656                                           "cyttsp", ts);
 657         if (error) {
 658                 dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
 659                         ts->irq, error);
 660                 return ERR_PTR(error);
 661         }
 662
 663         disable_irq(ts->irq);
 664
 665         cyttsp_hard_reset(ts);
 666
 667         error = cyttsp_power_on(ts);
 668         if (error)
 669                 return ERR_PTR(error);
 670
 671         error = input_register_device(input_dev);
 672         if (error) {
 673                 dev_err(ts->dev, "failed to register input device: %d\n",
 674                         error);
 675                 return ERR_PTR(error);
 676         }
 677
 678         return ts;
 679 }
 680 EXPORT_SYMBOL_GPL(cyttsp_probe);
 681
 682 MODULE_LICENSE("GPL");
 683 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
 684 MODULE_AUTHOR("Cypress");