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