drivers/input/touchscreen/tsc200x-core.c

   1 /*
   2  * TSC2004/TSC2005 touchscreen driver core
   3  *
   4  * Copyright (C) 2006-2010 Nokia Corporation
   5  * Copyright (C) 2015 QWERTY Embedded Design
   6  * Copyright (C) 2015 EMAC Inc.
   7  *
   8  * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
   9  * based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/input.h>
  25 #include <linux/input/touchscreen.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/delay.h>
  28 #include <linux/pm.h>
  29 #include <linux/of.h>
  30 #include <linux/spi/tsc2005.h>
  31 #include <linux/regulator/consumer.h>
  32 #include <linux/regmap.h>
  33 #include <linux/gpio/consumer.h>
  34 #include "tsc200x-core.h"
  35
  36 /*
  37  * The touchscreen interface operates as follows:
  38  *
  39  * 1) Pen is pressed against the touchscreen.
  40  * 2) TSC200X performs AD conversion.
  41  * 3) After the conversion is done TSC200X drives DAV line down.
  42  * 4) GPIO IRQ is received and tsc200x_irq_thread() is scheduled.
  43  * 5) tsc200x_irq_thread() queues up a transfer to fetch the x, y, z1, z2
  44  *    values.
  45  * 6) tsc200x_irq_thread() reports coordinates to input layer and sets up
  46  *    tsc200x_penup_timer() to be called after TSC200X_PENUP_TIME_MS (40ms).
  47  * 7) When the penup timer expires, there have not been touch or DAV interrupts
  48  *    during the last 40ms which means the pen has been lifted.
  49  *
  50  * ESD recovery via a hardware reset is done if the TSC200X doesn't respond
  51  * after a configurable period (in ms) of activity. If esd_timeout is 0, the
  52  * watchdog is disabled.
  53  */
  54
  55 static const struct regmap_range tsc200x_writable_ranges[] = {
  56         regmap_reg_range(TSC200X_REG_AUX_HIGH, TSC200X_REG_CFR2),
  57 };
  58
  59 static const struct regmap_access_table tsc200x_writable_table = {
  60         .yes_ranges = tsc200x_writable_ranges,
  61         .n_yes_ranges = ARRAY_SIZE(tsc200x_writable_ranges),
  62 };
  63
  64 const struct regmap_config tsc200x_regmap_config = {
  65         .reg_bits = 8,
  66         .val_bits = 16,
  67         .reg_stride = 0x08,
  68         .max_register = 0x78,
  69         .read_flag_mask = TSC200X_REG_READ,
  70         .write_flag_mask = TSC200X_REG_PND0,
  71         .wr_table = &tsc200x_writable_table,
  72         .use_single_rw = true,
  73 };
  74 EXPORT_SYMBOL_GPL(tsc200x_regmap_config);
  75
  76 struct tsc200x_data {
  77         u16 x;
  78         u16 y;
  79         u16 z1;
  80         u16 z2;
  81 } __packed;
  82 #define TSC200X_DATA_REGS 4
  83
  84 struct tsc200x {
  85         struct device           *dev;
  86         struct regmap           *regmap;
  87         __u16                   bustype;
  88
  89         struct input_dev        *idev;
  90         char                    phys[32];
  91
  92         struct mutex            mutex;
  93
  94         /* raw copy of previous x,y,z */
  95         int                     in_x;
  96         int                     in_y;
  97         int                     in_z1;
  98         int                     in_z2;
  99
 100         spinlock_t              lock;
 101         struct timer_list       penup_timer;
 102
 103         unsigned int            esd_timeout;
 104         struct delayed_work     esd_work;
 105         unsigned long           last_valid_interrupt;
 106
 107         unsigned int            x_plate_ohm;
 108
 109         bool                    opened;
 110         bool                    suspended;
 111
 112         bool                    pen_down;
 113
 114         struct regulator        *vio;
 115
 116         struct gpio_desc        *reset_gpio;
 117         void                    (*set_reset)(bool enable);
 118         int                     (*tsc200x_cmd)(struct device *dev, u8 cmd);
 119         int                     irq;
 120 };
 121
 122 static void tsc200x_update_pen_state(struct tsc200x *ts,
 123                                      int x, int y, int pressure)
 124 {
 125         if (pressure) {
 126                 input_report_abs(ts->idev, ABS_X, x);
 127                 input_report_abs(ts->idev, ABS_Y, y);
 128                 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
 129                 if (!ts->pen_down) {
 130                         input_report_key(ts->idev, BTN_TOUCH, !!pressure);
 131                         ts->pen_down = true;
 132                 }
 133         } else {
 134                 input_report_abs(ts->idev, ABS_PRESSURE, 0);
 135                 if (ts->pen_down) {
 136                         input_report_key(ts->idev, BTN_TOUCH, 0);
 137                         ts->pen_down = false;
 138                 }
 139         }
 140         input_sync(ts->idev);
 141         dev_dbg(ts->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
 142                 pressure);
 143 }
 144
 145 static irqreturn_t tsc200x_irq_thread(int irq, void *_ts)
 146 {
 147         struct tsc200x *ts = _ts;
 148         unsigned long flags;
 149         unsigned int pressure;
 150         struct tsc200x_data tsdata;
 151         int error;
 152
 153         /* read the coordinates */
 154         error = regmap_bulk_read(ts->regmap, TSC200X_REG_X, &tsdata,
 155                                  TSC200X_DATA_REGS);
 156         if (unlikely(error))
 157                 goto out;
 158
 159         /* validate position */
 160         if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT))
 161                 goto out;
 162
 163         /* Skip reading if the pressure components are out of range */
 164         if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT))
 165                 goto out;
 166         if (unlikely(tsdata.z1 >= tsdata.z2))
 167                 goto out;
 168
 169        /*
 170         * Skip point if this is a pen down with the exact same values as
 171         * the value before pen-up - that implies SPI fed us stale data
 172         */
 173         if (!ts->pen_down &&
 174             ts->in_x == tsdata.x && ts->in_y == tsdata.y &&
 175             ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) {
 176                 goto out;
 177         }
 178
 179         /*
 180          * At this point we are happy we have a valid and useful reading.
 181          * Remember it for later comparisons. We may now begin downsampling.
 182          */
 183         ts->in_x = tsdata.x;
 184         ts->in_y = tsdata.y;
 185         ts->in_z1 = tsdata.z1;
 186         ts->in_z2 = tsdata.z2;
 187
 188         /* Compute touch pressure resistance using equation #1 */
 189         pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1;
 190         pressure = pressure * ts->x_plate_ohm / 4096;
 191         if (unlikely(pressure > MAX_12BIT))
 192                 goto out;
 193
 194         spin_lock_irqsave(&ts->lock, flags);
 195
 196         tsc200x_update_pen_state(ts, tsdata.x, tsdata.y, pressure);
 197         mod_timer(&ts->penup_timer,
 198                   jiffies + msecs_to_jiffies(TSC200X_PENUP_TIME_MS));
 199
 200         spin_unlock_irqrestore(&ts->lock, flags);
 201
 202         ts->last_valid_interrupt = jiffies;
 203 out:
 204         return IRQ_HANDLED;
 205 }
 206
 207 static void tsc200x_penup_timer(unsigned long data)
 208 {
 209         struct tsc200x *ts = (struct tsc200x *)data;
 210         unsigned long flags;
 211
 212         spin_lock_irqsave(&ts->lock, flags);
 213         tsc200x_update_pen_state(ts, 0, 0, 0);
 214         spin_unlock_irqrestore(&ts->lock, flags);
 215 }
 216
 217 static void tsc200x_start_scan(struct tsc200x *ts)
 218 {
 219         regmap_write(ts->regmap, TSC200X_REG_CFR0, TSC200X_CFR0_INITVALUE);
 220         regmap_write(ts->regmap, TSC200X_REG_CFR1, TSC200X_CFR1_INITVALUE);
 221         regmap_write(ts->regmap, TSC200X_REG_CFR2, TSC200X_CFR2_INITVALUE);
 222         ts->tsc200x_cmd(ts->dev, TSC200X_CMD_NORMAL);
 223 }
 224
 225 static void tsc200x_stop_scan(struct tsc200x *ts)
 226 {
 227         ts->tsc200x_cmd(ts->dev, TSC200X_CMD_STOP);
 228 }
 229
 230 static void tsc200x_set_reset(struct tsc200x *ts, bool enable)
 231 {
 232         if (ts->reset_gpio)
 233                 gpiod_set_value_cansleep(ts->reset_gpio, enable);
 234         else if (ts->set_reset)
 235                 ts->set_reset(enable);
 236 }
 237
 238 /* must be called with ts->mutex held */
 239 static void __tsc200x_disable(struct tsc200x *ts)
 240 {
 241         tsc200x_stop_scan(ts);
 242
 243         disable_irq(ts->irq);
 244         del_timer_sync(&ts->penup_timer);
 245
 246         cancel_delayed_work_sync(&ts->esd_work);
 247
 248         enable_irq(ts->irq);
 249 }
 250
 251 /* must be called with ts->mutex held */
 252 static void __tsc200x_enable(struct tsc200x *ts)
 253 {
 254         tsc200x_start_scan(ts);
 255
 256         if (ts->esd_timeout && (ts->set_reset || ts->reset_gpio)) {
 257                 ts->last_valid_interrupt = jiffies;
 258                 schedule_delayed_work(&ts->esd_work,
 259                                 round_jiffies_relative(
 260                                         msecs_to_jiffies(ts->esd_timeout)));
 261         }
 262 }
 263
 264 static ssize_t tsc200x_selftest_show(struct device *dev,
 265                                      struct device_attribute *attr,
 266                                      char *buf)
 267 {
 268         struct tsc200x *ts = dev_get_drvdata(dev);
 269         unsigned int temp_high;
 270         unsigned int temp_high_orig;
 271         unsigned int temp_high_test;
 272         bool success = true;
 273         int error;
 274
 275         mutex_lock(&ts->mutex);
 276
 277         /*
 278          * Test TSC200X communications via temp high register.
 279          */
 280         __tsc200x_disable(ts);
 281
 282         error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high_orig);
 283         if (error) {
 284                 dev_warn(dev, "selftest failed: read error %d\n", error);
 285                 success = false;
 286                 goto out;
 287         }
 288
 289         temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
 290
 291         error = regmap_write(ts->regmap, TSC200X_REG_TEMP_HIGH, temp_high_test);
 292         if (error) {
 293                 dev_warn(dev, "selftest failed: write error %d\n", error);
 294                 success = false;
 295                 goto out;
 296         }
 297
 298         error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high);
 299         if (error) {
 300                 dev_warn(dev, "selftest failed: read error %d after write\n",
 301                          error);
 302                 success = false;
 303                 goto out;
 304         }
 305
 306         if (temp_high != temp_high_test) {
 307                 dev_warn(dev, "selftest failed: %d != %d\n",
 308                          temp_high, temp_high_test);
 309                 success = false;
 310         }
 311
 312         /* hardware reset */
 313         tsc200x_set_reset(ts, false);
 314         usleep_range(100, 500); /* only 10us required */
 315         tsc200x_set_reset(ts, true);
 316
 317         if (!success)
 318                 goto out;
 319
 320         /* test that the reset really happened */
 321         error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high);
 322         if (error) {
 323                 dev_warn(dev, "selftest failed: read error %d after reset\n",
 324                          error);
 325                 success = false;
 326                 goto out;
 327         }
 328
 329         if (temp_high != temp_high_orig) {
 330                 dev_warn(dev, "selftest failed after reset: %d != %d\n",
 331                          temp_high, temp_high_orig);
 332                 success = false;
 333         }
 334
 335 out:
 336         __tsc200x_enable(ts);
 337         mutex_unlock(&ts->mutex);
 338
 339         return sprintf(buf, "%d\n", success);
 340 }
 341
 342 static DEVICE_ATTR(selftest, S_IRUGO, tsc200x_selftest_show, NULL);
 343
 344 static struct attribute *tsc200x_attrs[] = {
 345         &dev_attr_selftest.attr,
 346         NULL
 347 };
 348
 349 static umode_t tsc200x_attr_is_visible(struct kobject *kobj,
 350                                       struct attribute *attr, int n)
 351 {
 352         struct device *dev = container_of(kobj, struct device, kobj);
 353         struct tsc200x *ts = dev_get_drvdata(dev);
 354         umode_t mode = attr->mode;
 355
 356         if (attr == &dev_attr_selftest.attr) {
 357                 if (!ts->set_reset && !ts->reset_gpio)
 358                         mode = 0;
 359         }
 360
 361         return mode;
 362 }
 363
 364 static const struct attribute_group tsc200x_attr_group = {
 365         .is_visible     = tsc200x_attr_is_visible,
 366         .attrs          = tsc200x_attrs,
 367 };
 368
 369 static void tsc200x_esd_work(struct work_struct *work)
 370 {
 371         struct tsc200x *ts = container_of(work, struct tsc200x, esd_work.work);
 372         int error;
 373         unsigned int r;
 374
 375         if (!mutex_trylock(&ts->mutex)) {
 376                 /*
 377                  * If the mutex is taken, it means that disable or enable is in
 378                  * progress. In that case just reschedule the work. If the work
 379                  * is not needed, it will be canceled by disable.
 380                  */
 381                 goto reschedule;
 382         }
 383
 384         if (time_is_after_jiffies(ts->last_valid_interrupt +
 385                                   msecs_to_jiffies(ts->esd_timeout)))
 386                 goto out;
 387
 388         /* We should be able to read register without disabling interrupts. */
 389         error = regmap_read(ts->regmap, TSC200X_REG_CFR0, &r);
 390         if (!error &&
 391             !((r ^ TSC200X_CFR0_INITVALUE) & TSC200X_CFR0_RW_MASK)) {
 392                 goto out;
 393         }
 394
 395         /*
 396          * If we could not read our known value from configuration register 0
 397          * then we should reset the controller as if from power-up and start
 398          * scanning again.
 399          */
 400         dev_info(ts->dev, "TSC200X not responding - resetting\n");
 401
 402         disable_irq(ts->irq);
 403         del_timer_sync(&ts->penup_timer);
 404
 405         tsc200x_update_pen_state(ts, 0, 0, 0);
 406
 407         tsc200x_set_reset(ts, false);
 408         usleep_range(100, 500); /* only 10us required */
 409         tsc200x_set_reset(ts, true);
 410
 411         enable_irq(ts->irq);
 412         tsc200x_start_scan(ts);
 413
 414 out:
 415         mutex_unlock(&ts->mutex);
 416 reschedule:
 417         /* re-arm the watchdog */
 418         schedule_delayed_work(&ts->esd_work,
 419                               round_jiffies_relative(
 420                                         msecs_to_jiffies(ts->esd_timeout)));
 421 }
 422
 423 static int tsc200x_open(struct input_dev *input)
 424 {
 425         struct tsc200x *ts = input_get_drvdata(input);
 426
 427         mutex_lock(&ts->mutex);
 428
 429         if (!ts->suspended)
 430                 __tsc200x_enable(ts);
 431
 432         ts->opened = true;
 433
 434         mutex_unlock(&ts->mutex);
 435
 436         return 0;
 437 }
 438
 439 static void tsc200x_close(struct input_dev *input)
 440 {
 441         struct tsc200x *ts = input_get_drvdata(input);
 442
 443         mutex_lock(&ts->mutex);
 444
 445         if (!ts->suspended)
 446                 __tsc200x_disable(ts);
 447
 448         ts->opened = false;
 449
 450         mutex_unlock(&ts->mutex);
 451 }
 452
 453 int tsc200x_probe(struct device *dev, int irq, const struct input_id *tsc_id,
 454                   struct regmap *regmap,
 455                   int (*tsc200x_cmd)(struct device *dev, u8 cmd))
 456 {
 457         const struct tsc2005_platform_data *pdata = dev_get_platdata(dev);
 458         struct device_node *np = dev->of_node;
 459
 460         struct tsc200x *ts;
 461         struct input_dev *input_dev;
 462         unsigned int max_x = MAX_12BIT;
 463         unsigned int max_y = MAX_12BIT;
 464         unsigned int max_p = MAX_12BIT;
 465         unsigned int fudge_x = TSC200X_DEF_X_FUZZ;
 466         unsigned int fudge_y = TSC200X_DEF_Y_FUZZ;
 467         unsigned int fudge_p = TSC200X_DEF_P_FUZZ;
 468         unsigned int x_plate_ohm = TSC200X_DEF_RESISTOR;
 469         unsigned int esd_timeout;
 470         int error;
 471
 472         if (!np && !pdata) {
 473                 dev_err(dev, "no platform data\n");
 474                 return -ENODEV;
 475         }
 476
 477         if (irq <= 0) {
 478                 dev_err(dev, "no irq\n");
 479                 return -ENODEV;
 480         }
 481
 482         if (IS_ERR(regmap))
 483                 return PTR_ERR(regmap);
 484
 485         if (!tsc200x_cmd) {
 486                 dev_err(dev, "no cmd function\n");
 487                 return -ENODEV;
 488         }
 489
 490         if (pdata) {
 491                 fudge_x = pdata->ts_x_fudge;
 492                 fudge_y = pdata->ts_y_fudge;
 493                 fudge_p = pdata->ts_pressure_fudge;
 494                 max_x   = pdata->ts_x_max;
 495                 max_y   = pdata->ts_y_max;
 496                 max_p   = pdata->ts_pressure_max;
 497                 x_plate_ohm = pdata->ts_x_plate_ohm;
 498                 esd_timeout = pdata->esd_timeout_ms;
 499         } else {
 500                 x_plate_ohm = TSC200X_DEF_RESISTOR;
 501                 of_property_read_u32(np, "ti,x-plate-ohms", &x_plate_ohm);
 502                 esd_timeout = 0;
 503                 of_property_read_u32(np, "ti,esd-recovery-timeout-ms",
 504                                                                 &esd_timeout);
 505         }
 506
 507         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 508         if (!ts)
 509                 return -ENOMEM;
 510
 511         input_dev = devm_input_allocate_device(dev);
 512         if (!input_dev)
 513                 return -ENOMEM;
 514
 515         ts->irq = irq;
 516         ts->dev = dev;
 517         ts->idev = input_dev;
 518         ts->regmap = regmap;
 519         ts->tsc200x_cmd = tsc200x_cmd;
 520         ts->x_plate_ohm = x_plate_ohm;
 521         ts->esd_timeout = esd_timeout;
 522
 523         ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 524         if (IS_ERR(ts->reset_gpio)) {
 525                 error = PTR_ERR(ts->reset_gpio);
 526                 dev_err(dev, "error acquiring reset gpio: %d\n", error);
 527                 return error;
 528         }
 529
 530         ts->vio = devm_regulator_get_optional(dev, "vio");
 531         if (IS_ERR(ts->vio)) {
 532                 error = PTR_ERR(ts->vio);
 533                 dev_err(dev, "vio regulator missing (%d)", error);
 534                 return error;
 535         }
 536
 537         if (!ts->reset_gpio && pdata)
 538                 ts->set_reset = pdata->set_reset;
 539
 540         mutex_init(&ts->mutex);
 541
 542         spin_lock_init(&ts->lock);
 543         setup_timer(&ts->penup_timer, tsc200x_penup_timer, (unsigned long)ts);
 544
 545         INIT_DELAYED_WORK(&ts->esd_work, tsc200x_esd_work);
 546
 547         snprintf(ts->phys, sizeof(ts->phys),
 548                  "%s/input-ts", dev_name(dev));
 549
 550         if (tsc_id->product == 2004) {
 551                 input_dev->name = "TSC200X touchscreen";
 552         } else {
 553                 input_dev->name = devm_kasprintf(dev, GFP_KERNEL,
 554                                                  "TSC%04d touchscreen",
 555                                                  tsc_id->product);
 556                 if (!input_dev->name)
 557                         return -ENOMEM;
 558         }
 559
 560         input_dev->phys = ts->phys;
 561         input_dev->id = *tsc_id;
 562         input_dev->dev.parent = dev;
 563         input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
 564         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 565
 566         input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
 567         input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
 568         input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
 569
 570         if (np)
 571                 touchscreen_parse_properties(input_dev, false);
 572
 573         input_dev->open = tsc200x_open;
 574         input_dev->close = tsc200x_close;
 575
 576         input_set_drvdata(input_dev, ts);
 577
 578         /* Ensure the touchscreen is off */
 579         tsc200x_stop_scan(ts);
 580
 581         error = devm_request_threaded_irq(dev, irq, NULL,
 582                                           tsc200x_irq_thread,
 583                                           IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 584                                           "tsc200x", ts);
 585         if (error) {
 586                 dev_err(dev, "Failed to request irq, err: %d\n", error);
 587                 return error;
 588         }
 589
 590         /* enable regulator for DT */
 591         if (ts->vio) {
 592                 error = regulator_enable(ts->vio);
 593                 if (error)
 594                         return error;
 595         }
 596
 597         dev_set_drvdata(dev, ts);
 598         error = sysfs_create_group(&dev->kobj, &tsc200x_attr_group);
 599         if (error) {
 600                 dev_err(dev,
 601                         "Failed to create sysfs attributes, err: %d\n", error);
 602                 goto disable_regulator;
 603         }
 604
 605         error = input_register_device(ts->idev);
 606         if (error) {
 607                 dev_err(dev,
 608                         "Failed to register input device, err: %d\n", error);
 609                 goto err_remove_sysfs;
 610         }
 611
 612         irq_set_irq_wake(irq, 1);
 613         return 0;
 614
 615 err_remove_sysfs:
 616         sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
 617 disable_regulator:
 618         if (ts->vio)
 619                 regulator_disable(ts->vio);
 620         return error;
 621 }
 622 EXPORT_SYMBOL_GPL(tsc200x_probe);
 623
 624 int tsc200x_remove(struct device *dev)
 625 {
 626         struct tsc200x *ts = dev_get_drvdata(dev);
 627
 628         sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
 629
 630         if (ts->vio)
 631                 regulator_disable(ts->vio);
 632
 633         return 0;
 634 }
 635 EXPORT_SYMBOL_GPL(tsc200x_remove);
 636
 637 static int __maybe_unused tsc200x_suspend(struct device *dev)
 638 {
 639         struct tsc200x *ts = dev_get_drvdata(dev);
 640
 641         mutex_lock(&ts->mutex);
 642
 643         if (!ts->suspended && ts->opened)
 644                 __tsc200x_disable(ts);
 645
 646         ts->suspended = true;
 647
 648         mutex_unlock(&ts->mutex);
 649
 650         return 0;
 651 }
 652
 653 static int __maybe_unused tsc200x_resume(struct device *dev)
 654 {
 655         struct tsc200x *ts = dev_get_drvdata(dev);
 656
 657         mutex_lock(&ts->mutex);
 658
 659         if (ts->suspended && ts->opened)
 660                 __tsc200x_enable(ts);
 661
 662         ts->suspended = false;
 663
 664         mutex_unlock(&ts->mutex);
 665
 666         return 0;
 667 }
 668
 669 SIMPLE_DEV_PM_OPS(tsc200x_pm_ops, tsc200x_suspend, tsc200x_resume);
 670 EXPORT_SYMBOL_GPL(tsc200x_pm_ops);
 671
 672 MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
 673 MODULE_DESCRIPTION("TSC200x Touchscreen Driver Core");
 674 MODULE_LICENSE("GPL");