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