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