drivers/input/touchscreen/ad7879.c

   1 /*
   2  * AD7879/AD7889 based touchscreen and GPIO driver
   3  *
   4  * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  *
   8  * History:
   9  * Copyright (c) 2005 David Brownell
  10  * Copyright (c) 2006 Nokia Corporation
  11  * Various changes: Imre Deak <imre.deak@nokia.com>
  12  *
  13  * Using code from:
  14  *  - corgi_ts.c
  15  *      Copyright (C) 2004-2005 Richard Purdie
  16  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  17  *      Copyright (C) 2002 MontaVista Software
  18  *      Copyright (C) 2004 Texas Instruments
  19  *      Copyright (C) 2005 Dirk Behme
  20  *  - ad7877.c
  21  *      Copyright (C) 2006-2008 Analog Devices Inc.
  22  */
  23
  24 #include <linux/device.h>
  25 #include <linux/init.h>
  26 #include <linux/delay.h>
  27 #include <linux/input.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/irq.h>
  30 #include <linux/slab.h>
  31 #include <linux/spi/spi.h>
  32 #include <linux/i2c.h>
  33 #include <linux/gpio.h>
  34
  35 #include <linux/spi/ad7879.h>
  36 #include <linux/module.h>
  37 #include "ad7879.h"
  38
  39 #define AD7879_REG_ZEROS                0
  40 #define AD7879_REG_CTRL1                1
  41 #define AD7879_REG_CTRL2                2
  42 #define AD7879_REG_CTRL3                3
  43 #define AD7879_REG_AUX1HIGH             4
  44 #define AD7879_REG_AUX1LOW              5
  45 #define AD7879_REG_TEMP1HIGH            6
  46 #define AD7879_REG_TEMP1LOW             7
  47 #define AD7879_REG_XPLUS                8
  48 #define AD7879_REG_YPLUS                9
  49 #define AD7879_REG_Z1                   10
  50 #define AD7879_REG_Z2                   11
  51 #define AD7879_REG_AUXVBAT              12
  52 #define AD7879_REG_TEMP                 13
  53 #define AD7879_REG_REVID                14
  54
  55 /* Control REG 1 */
  56 #define AD7879_TMR(x)                   ((x & 0xFF) << 0)
  57 #define AD7879_ACQ(x)                   ((x & 0x3) << 8)
  58 #define AD7879_MODE_NOC                 (0 << 10)       /* Do not convert */
  59 #define AD7879_MODE_SCC                 (1 << 10)       /* Single channel conversion */
  60 #define AD7879_MODE_SEQ0                (2 << 10)       /* Sequence 0 in Slave Mode */
  61 #define AD7879_MODE_SEQ1                (3 << 10)       /* Sequence 1 in Master Mode */
  62 #define AD7879_MODE_INT                 (1 << 15)       /* PENIRQ disabled INT enabled */
  63
  64 /* Control REG 2 */
  65 #define AD7879_FCD(x)                   ((x & 0x3) << 0)
  66 #define AD7879_RESET                    (1 << 4)
  67 #define AD7879_MFS(x)                   ((x & 0x3) << 5)
  68 #define AD7879_AVG(x)                   ((x & 0x3) << 7)
  69 #define AD7879_SER                      (1 << 9)        /* non-differential */
  70 #define AD7879_DFR                      (0 << 9)        /* differential */
  71 #define AD7879_GPIOPOL                  (1 << 10)
  72 #define AD7879_GPIODIR                  (1 << 11)
  73 #define AD7879_GPIO_DATA                (1 << 12)
  74 #define AD7879_GPIO_EN                  (1 << 13)
  75 #define AD7879_PM(x)                    ((x & 0x3) << 14)
  76 #define AD7879_PM_SHUTDOWN              (0)
  77 #define AD7879_PM_DYN                   (1)
  78 #define AD7879_PM_FULLON                (2)
  79
  80 /* Control REG 3 */
  81 #define AD7879_TEMPMASK_BIT             (1<<15)
  82 #define AD7879_AUXVBATMASK_BIT          (1<<14)
  83 #define AD7879_INTMODE_BIT              (1<<13)
  84 #define AD7879_GPIOALERTMASK_BIT        (1<<12)
  85 #define AD7879_AUXLOW_BIT               (1<<11)
  86 #define AD7879_AUXHIGH_BIT              (1<<10)
  87 #define AD7879_TEMPLOW_BIT              (1<<9)
  88 #define AD7879_TEMPHIGH_BIT             (1<<8)
  89 #define AD7879_YPLUS_BIT                (1<<7)
  90 #define AD7879_XPLUS_BIT                (1<<6)
  91 #define AD7879_Z1_BIT                   (1<<5)
  92 #define AD7879_Z2_BIT                   (1<<4)
  93 #define AD7879_AUX_BIT                  (1<<3)
  94 #define AD7879_VBAT_BIT                 (1<<2)
  95 #define AD7879_TEMP_BIT                 (1<<1)
  96
  97 enum {
  98         AD7879_SEQ_XPOS  = 0,
  99         AD7879_SEQ_YPOS  = 1,
 100         AD7879_SEQ_Z1    = 2,
 101         AD7879_SEQ_Z2    = 3,
 102         AD7879_NR_SENSE  = 4,
 103 };
 104
 105 #define MAX_12BIT                       ((1<<12)-1)
 106 #define TS_PEN_UP_TIMEOUT               msecs_to_jiffies(50)
 107
 108 struct ad7879 {
 109         const struct ad7879_bus_ops *bops;
 110
 111         struct device           *dev;
 112         struct input_dev        *input;
 113         struct timer_list       timer;
 114 #ifdef CONFIG_GPIOLIB
 115         struct gpio_chip        gc;
 116         struct mutex            mutex;
 117 #endif
 118         unsigned int            irq;
 119         bool                    disabled;       /* P: input->mutex */
 120         bool                    suspended;      /* P: input->mutex */
 121         bool                    swap_xy;
 122         u16                     conversion_data[AD7879_NR_SENSE];
 123         char                    phys[32];
 124         u8                      first_conversion_delay;
 125         u8                      acquisition_time;
 126         u8                      averaging;
 127         u8                      pen_down_acc_interval;
 128         u8                      median;
 129         u16                     x_plate_ohms;
 130         u16                     pressure_max;
 131         u16                     cmd_crtl1;
 132         u16                     cmd_crtl2;
 133         u16                     cmd_crtl3;
 134         int                     x;
 135         int                     y;
 136         int                     Rt;
 137 };
 138
 139 static int ad7879_read(struct ad7879 *ts, u8 reg)
 140 {
 141         return ts->bops->read(ts->dev, reg);
 142 }
 143
 144 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
 145 {
 146         return ts->bops->multi_read(ts->dev, first_reg, count, buf);
 147 }
 148
 149 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
 150 {
 151         return ts->bops->write(ts->dev, reg, val);
 152 }
 153
 154 static int ad7879_report(struct ad7879 *ts)
 155 {
 156         struct input_dev *input_dev = ts->input;
 157         unsigned Rt;
 158         u16 x, y, z1, z2;
 159
 160         x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
 161         y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
 162         z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
 163         z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
 164
 165         if (ts->swap_xy)
 166                 swap(x, y);
 167
 168         /*
 169          * The samples processed here are already preprocessed by the AD7879.
 170          * The preprocessing function consists of a median and an averaging
 171          * filter.  The combination of these two techniques provides a robust
 172          * solution, discarding the spurious noise in the signal and keeping
 173          * only the data of interest.  The size of both filters is
 174          * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
 175          * user-programmable conversion controls include variable acquisition
 176          * time, and first conversion delay. Up to 16 averages can be taken
 177          * per conversion.
 178          */
 179
 180         if (likely(x && z1)) {
 181                 /* compute touch pressure resistance using equation #1 */
 182                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 183                 Rt /= z1;
 184                 Rt = (Rt + 2047) >> 12;
 185
 186                 /*
 187                  * Sample found inconsistent, pressure is beyond
 188                  * the maximum. Don't report it to user space.
 189                  */
 190                 if (Rt > ts->pressure_max)
 191                         return -EINVAL;
 192
 193                 /*
 194                  * Note that we delay reporting events by one sample.
 195                  * This is done to avoid reporting last sample of the
 196                  * touch sequence, which may be incomplete if finger
 197                  * leaves the surface before last reading is taken.
 198                  */
 199                 if (timer_pending(&ts->timer)) {
 200                         /* Touch continues */
 201                         input_report_key(input_dev, BTN_TOUCH, 1);
 202                         input_report_abs(input_dev, ABS_X, ts->x);
 203                         input_report_abs(input_dev, ABS_Y, ts->y);
 204                         input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
 205                         input_sync(input_dev);
 206                 }
 207
 208                 ts->x = x;
 209                 ts->y = y;
 210                 ts->Rt = Rt;
 211
 212                 return 0;
 213         }
 214
 215         return -EINVAL;
 216 }
 217
 218 static void ad7879_ts_event_release(struct ad7879 *ts)
 219 {
 220         struct input_dev *input_dev = ts->input;
 221
 222         input_report_abs(input_dev, ABS_PRESSURE, 0);
 223         input_report_key(input_dev, BTN_TOUCH, 0);
 224         input_sync(input_dev);
 225 }
 226
 227 static void ad7879_timer(unsigned long handle)
 228 {
 229         struct ad7879 *ts = (void *)handle;
 230
 231         ad7879_ts_event_release(ts);
 232 }
 233
 234 static irqreturn_t ad7879_irq(int irq, void *handle)
 235 {
 236         struct ad7879 *ts = handle;
 237
 238         ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
 239
 240         if (!ad7879_report(ts))
 241                 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 242
 243         return IRQ_HANDLED;
 244 }
 245
 246 static void __ad7879_enable(struct ad7879 *ts)
 247 {
 248         ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 249         ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
 250         ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
 251
 252         enable_irq(ts->irq);
 253 }
 254
 255 static void __ad7879_disable(struct ad7879 *ts)
 256 {
 257         u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
 258                 AD7879_PM(AD7879_PM_SHUTDOWN);
 259         disable_irq(ts->irq);
 260
 261         if (del_timer_sync(&ts->timer))
 262                 ad7879_ts_event_release(ts);
 263
 264         ad7879_write(ts, AD7879_REG_CTRL2, reg);
 265 }
 266
 267
 268 static int ad7879_open(struct input_dev *input)
 269 {
 270         struct ad7879 *ts = input_get_drvdata(input);
 271
 272         /* protected by input->mutex */
 273         if (!ts->disabled && !ts->suspended)
 274                 __ad7879_enable(ts);
 275
 276         return 0;
 277 }
 278
 279 static void ad7879_close(struct input_dev* input)
 280 {
 281         struct ad7879 *ts = input_get_drvdata(input);
 282
 283         /* protected by input->mutex */
 284         if (!ts->disabled && !ts->suspended)
 285                 __ad7879_disable(ts);
 286 }
 287
 288 #ifdef CONFIG_PM_SLEEP
 289 static int ad7879_suspend(struct device *dev)
 290 {
 291         struct ad7879 *ts = dev_get_drvdata(dev);
 292
 293         mutex_lock(&ts->input->mutex);
 294
 295         if (!ts->suspended && !ts->disabled && ts->input->users)
 296                 __ad7879_disable(ts);
 297
 298         ts->suspended = true;
 299
 300         mutex_unlock(&ts->input->mutex);
 301
 302         return 0;
 303 }
 304
 305 static int ad7879_resume(struct device *dev)
 306 {
 307         struct ad7879 *ts = dev_get_drvdata(dev);
 308
 309         mutex_lock(&ts->input->mutex);
 310
 311         if (ts->suspended && !ts->disabled && ts->input->users)
 312                 __ad7879_enable(ts);
 313
 314         ts->suspended = false;
 315
 316         mutex_unlock(&ts->input->mutex);
 317
 318         return 0;
 319 }
 320 #endif
 321
 322 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
 323 EXPORT_SYMBOL(ad7879_pm_ops);
 324
 325 static void ad7879_toggle(struct ad7879 *ts, bool disable)
 326 {
 327         mutex_lock(&ts->input->mutex);
 328
 329         if (!ts->suspended && ts->input->users != 0) {
 330
 331                 if (disable) {
 332                         if (ts->disabled)
 333                                 __ad7879_enable(ts);
 334                 } else {
 335                         if (!ts->disabled)
 336                                 __ad7879_disable(ts);
 337                 }
 338         }
 339
 340         ts->disabled = disable;
 341
 342         mutex_unlock(&ts->input->mutex);
 343 }
 344
 345 static ssize_t ad7879_disable_show(struct device *dev,
 346                                      struct device_attribute *attr, char *buf)
 347 {
 348         struct ad7879 *ts = dev_get_drvdata(dev);
 349
 350         return sprintf(buf, "%u\n", ts->disabled);
 351 }
 352
 353 static ssize_t ad7879_disable_store(struct device *dev,
 354                                      struct device_attribute *attr,
 355                                      const char *buf, size_t count)
 356 {
 357         struct ad7879 *ts = dev_get_drvdata(dev);
 358         unsigned int val;
 359         int error;
 360
 361         error = kstrtouint(buf, 10, &val);
 362         if (error)
 363                 return error;
 364
 365         ad7879_toggle(ts, val);
 366
 367         return count;
 368 }
 369
 370 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
 371
 372 static struct attribute *ad7879_attributes[] = {
 373         &dev_attr_disable.attr,
 374         NULL
 375 };
 376
 377 static const struct attribute_group ad7879_attr_group = {
 378         .attrs = ad7879_attributes,
 379 };
 380
 381 #ifdef CONFIG_GPIOLIB
 382 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
 383                                         unsigned gpio)
 384 {
 385         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 386         int err;
 387
 388         mutex_lock(&ts->mutex);
 389         ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
 390         err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 391         mutex_unlock(&ts->mutex);
 392
 393         return err;
 394 }
 395
 396 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
 397                                         unsigned gpio, int level)
 398 {
 399         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 400         int err;
 401
 402         mutex_lock(&ts->mutex);
 403         ts->cmd_crtl2 &= ~AD7879_GPIODIR;
 404         ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
 405         if (level)
 406                 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
 407         else
 408                 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
 409
 410         err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 411         mutex_unlock(&ts->mutex);
 412
 413         return err;
 414 }
 415
 416 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 417 {
 418         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 419         u16 val;
 420
 421         mutex_lock(&ts->mutex);
 422         val = ad7879_read(ts, AD7879_REG_CTRL2);
 423         mutex_unlock(&ts->mutex);
 424
 425         return !!(val & AD7879_GPIO_DATA);
 426 }
 427
 428 static void ad7879_gpio_set_value(struct gpio_chip *chip,
 429                                   unsigned gpio, int value)
 430 {
 431         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 432
 433         mutex_lock(&ts->mutex);
 434         if (value)
 435                 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
 436         else
 437                 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
 438
 439         ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 440         mutex_unlock(&ts->mutex);
 441 }
 442
 443 static int ad7879_gpio_add(struct ad7879 *ts,
 444                            const struct ad7879_platform_data *pdata)
 445 {
 446         int ret = 0;
 447
 448         mutex_init(&ts->mutex);
 449
 450         if (pdata->gpio_export) {
 451                 ts->gc.direction_input = ad7879_gpio_direction_input;
 452                 ts->gc.direction_output = ad7879_gpio_direction_output;
 453                 ts->gc.get = ad7879_gpio_get_value;
 454                 ts->gc.set = ad7879_gpio_set_value;
 455                 ts->gc.can_sleep = 1;
 456                 ts->gc.base = pdata->gpio_base;
 457                 ts->gc.ngpio = 1;
 458                 ts->gc.label = "AD7879-GPIO";
 459                 ts->gc.owner = THIS_MODULE;
 460                 ts->gc.dev = ts->dev;
 461
 462                 ret = gpiochip_add(&ts->gc);
 463                 if (ret)
 464                         dev_err(ts->dev, "failed to register gpio %d\n",
 465                                 ts->gc.base);
 466         }
 467
 468         return ret;
 469 }
 470
 471 static void ad7879_gpio_remove(struct ad7879 *ts)
 472 {
 473         const struct ad7879_platform_data *pdata = ts->dev->platform_data;
 474         int ret;
 475
 476         if (pdata->gpio_export) {
 477                 ret = gpiochip_remove(&ts->gc);
 478                 if (ret)
 479                         dev_err(ts->dev, "failed to remove gpio %d\n",
 480                                 ts->gc.base);
 481         }
 482 }
 483 #else
 484 static inline int ad7879_gpio_add(struct ad7879 *ts,
 485                                   const struct ad7879_platform_data *pdata)
 486 {
 487         return 0;
 488 }
 489
 490 static inline void ad7879_gpio_remove(struct ad7879 *ts)
 491 {
 492 }
 493 #endif
 494
 495 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
 496                             const struct ad7879_bus_ops *bops)
 497 {
 498         struct ad7879_platform_data *pdata = dev->platform_data;
 499         struct ad7879 *ts;
 500         struct input_dev *input_dev;
 501         int err;
 502         u16 revid;
 503
 504         if (!irq) {
 505                 dev_err(dev, "no IRQ?\n");
 506                 err = -EINVAL;
 507                 goto err_out;
 508         }
 509
 510         if (!pdata) {
 511                 dev_err(dev, "no platform data?\n");
 512                 err = -EINVAL;
 513                 goto err_out;
 514         }
 515
 516         ts = kzalloc(sizeof(*ts), GFP_KERNEL);
 517         input_dev = input_allocate_device();
 518         if (!ts || !input_dev) {
 519                 err = -ENOMEM;
 520                 goto err_free_mem;
 521         }
 522
 523         ts->bops = bops;
 524         ts->dev = dev;
 525         ts->input = input_dev;
 526         ts->irq = irq;
 527         ts->swap_xy = pdata->swap_xy;
 528
 529         setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
 530
 531         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 532         ts->pressure_max = pdata->pressure_max ? : ~0;
 533
 534         ts->first_conversion_delay = pdata->first_conversion_delay;
 535         ts->acquisition_time = pdata->acquisition_time;
 536         ts->averaging = pdata->averaging;
 537         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 538         ts->median = pdata->median;
 539
 540         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
 541
 542         input_dev->name = "AD7879 Touchscreen";
 543         input_dev->phys = ts->phys;
 544         input_dev->dev.parent = dev;
 545         input_dev->id.bustype = bops->bustype;
 546
 547         input_dev->open = ad7879_open;
 548         input_dev->close = ad7879_close;
 549
 550         input_set_drvdata(input_dev, ts);
 551
 552         __set_bit(EV_ABS, input_dev->evbit);
 553         __set_bit(ABS_X, input_dev->absbit);
 554         __set_bit(ABS_Y, input_dev->absbit);
 555         __set_bit(ABS_PRESSURE, input_dev->absbit);
 556
 557         __set_bit(EV_KEY, input_dev->evbit);
 558         __set_bit(BTN_TOUCH, input_dev->keybit);
 559
 560         input_set_abs_params(input_dev, ABS_X,
 561                         pdata->x_min ? : 0,
 562                         pdata->x_max ? : MAX_12BIT,
 563                         0, 0);
 564         input_set_abs_params(input_dev, ABS_Y,
 565                         pdata->y_min ? : 0,
 566                         pdata->y_max ? : MAX_12BIT,
 567                         0, 0);
 568         input_set_abs_params(input_dev, ABS_PRESSURE,
 569                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 570
 571         err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
 572         if (err < 0) {
 573                 dev_err(dev, "Failed to write %s\n", input_dev->name);
 574                 goto err_free_mem;
 575         }
 576
 577         revid = ad7879_read(ts, AD7879_REG_REVID);
 578         input_dev->id.product = (revid & 0xff);
 579         input_dev->id.version = revid >> 8;
 580         if (input_dev->id.product != devid) {
 581                 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
 582                         input_dev->name, devid, revid);
 583                 err = -ENODEV;
 584                 goto err_free_mem;
 585         }
 586
 587         ts->cmd_crtl3 = AD7879_YPLUS_BIT |
 588                         AD7879_XPLUS_BIT |
 589                         AD7879_Z2_BIT |
 590                         AD7879_Z1_BIT |
 591                         AD7879_TEMPMASK_BIT |
 592                         AD7879_AUXVBATMASK_BIT |
 593                         AD7879_GPIOALERTMASK_BIT;
 594
 595         ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
 596                         AD7879_AVG(ts->averaging) |
 597                         AD7879_MFS(ts->median) |
 598                         AD7879_FCD(ts->first_conversion_delay);
 599
 600         ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
 601                         AD7879_ACQ(ts->acquisition_time) |
 602                         AD7879_TMR(ts->pen_down_acc_interval);
 603
 604         err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
 605                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 606                                    dev_name(dev), ts);
 607         if (err) {
 608                 dev_err(dev, "irq %d busy?\n", ts->irq);
 609                 goto err_free_mem;
 610         }
 611
 612         __ad7879_disable(ts);
 613
 614         err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
 615         if (err)
 616                 goto err_free_irq;
 617
 618         err = ad7879_gpio_add(ts, pdata);
 619         if (err)
 620                 goto err_remove_attr;
 621
 622         err = input_register_device(input_dev);
 623         if (err)
 624                 goto err_remove_gpio;
 625
 626         return ts;
 627
 628 err_remove_gpio:
 629         ad7879_gpio_remove(ts);
 630 err_remove_attr:
 631         sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
 632 err_free_irq:
 633         free_irq(ts->irq, ts);
 634 err_free_mem:
 635         input_free_device(input_dev);
 636         kfree(ts);
 637 err_out:
 638         return ERR_PTR(err);
 639 }
 640 EXPORT_SYMBOL(ad7879_probe);
 641
 642 void ad7879_remove(struct ad7879 *ts)
 643 {
 644         ad7879_gpio_remove(ts);
 645         sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
 646         free_irq(ts->irq, ts);
 647         input_unregister_device(ts->input);
 648         kfree(ts);
 649 }
 650 EXPORT_SYMBOL(ad7879_remove);
 651
 652 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 653 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
 654 MODULE_LICENSE("GPL");