drivers/input/touchscreen/ad7879.c

   1 /*
   2  * Copyright (C) 2008-2009 Michael Hennerich, Analog Devices Inc.
   3  *
   4  * Description: AD7879/AD7889 based touchscreen, and GPIO driver
   5  *              (I2C/SPI Interface)
   6  *
   7  * Bugs:        Enter bugs at http://blackfin.uclinux.org/
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, see the file COPYING, or write
  21  * to the Free Software Foundation, Inc.,
  22  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  23  *
  24  * History:
  25  * Copyright (c) 2005 David Brownell
  26  * Copyright (c) 2006 Nokia Corporation
  27  * Various changes: Imre Deak <imre.deak@nokia.com>
  28  *
  29  * Using code from:
  30  *  - corgi_ts.c
  31  *      Copyright (C) 2004-2005 Richard Purdie
  32  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  33  *      Copyright (C) 2002 MontaVista Software
  34  *      Copyright (C) 2004 Texas Instruments
  35  *      Copyright (C) 2005 Dirk Behme
  36  *  - ad7877.c
  37  *      Copyright (C) 2006-2008 Analog Devices Inc.
  38  */
  39
  40 #include <linux/device.h>
  41 #include <linux/init.h>
  42 #include <linux/delay.h>
  43 #include <linux/input.h>
  44 #include <linux/interrupt.h>
  45 #include <linux/irq.h>
  46 #include <linux/slab.h>
  47 #include <linux/workqueue.h>
  48 #include <linux/spi/spi.h>
  49 #include <linux/i2c.h>
  50 #include <linux/gpio.h>
  51
  52 #include <linux/spi/ad7879.h>
  53
  54 #define AD7879_REG_ZEROS                0
  55 #define AD7879_REG_CTRL1                1
  56 #define AD7879_REG_CTRL2                2
  57 #define AD7879_REG_CTRL3                3
  58 #define AD7879_REG_AUX1HIGH             4
  59 #define AD7879_REG_AUX1LOW              5
  60 #define AD7879_REG_TEMP1HIGH            6
  61 #define AD7879_REG_TEMP1LOW             7
  62 #define AD7879_REG_XPLUS                8
  63 #define AD7879_REG_YPLUS                9
  64 #define AD7879_REG_Z1                   10
  65 #define AD7879_REG_Z2                   11
  66 #define AD7879_REG_AUXVBAT              12
  67 #define AD7879_REG_TEMP                 13
  68 #define AD7879_REG_REVID                14
  69
  70 /* Control REG 1 */
  71 #define AD7879_TMR(x)                   ((x & 0xFF) << 0)
  72 #define AD7879_ACQ(x)                   ((x & 0x3) << 8)
  73 #define AD7879_MODE_NOC                 (0 << 10)       /* Do not convert */
  74 #define AD7879_MODE_SCC                 (1 << 10)       /* Single channel conversion */
  75 #define AD7879_MODE_SEQ0                (2 << 10)       /* Sequence 0 in Slave Mode */
  76 #define AD7879_MODE_SEQ1                (3 << 10)       /* Sequence 1 in Master Mode */
  77 #define AD7879_MODE_INT                 (1 << 15)       /* PENIRQ disabled INT enabled */
  78
  79 /* Control REG 2 */
  80 #define AD7879_FCD(x)                   ((x & 0x3) << 0)
  81 #define AD7879_RESET                    (1 << 4)
  82 #define AD7879_MFS(x)                   ((x & 0x3) << 5)
  83 #define AD7879_AVG(x)                   ((x & 0x3) << 7)
  84 #define AD7879_SER                      (1 << 9)        /* non-differential */
  85 #define AD7879_DFR                      (0 << 9)        /* differential */
  86 #define AD7879_GPIOPOL                  (1 << 10)
  87 #define AD7879_GPIODIR                  (1 << 11)
  88 #define AD7879_GPIO_DATA                (1 << 12)
  89 #define AD7879_GPIO_EN                  (1 << 13)
  90 #define AD7879_PM(x)                    ((x & 0x3) << 14)
  91 #define AD7879_PM_SHUTDOWN              (0)
  92 #define AD7879_PM_DYN                   (1)
  93 #define AD7879_PM_FULLON                (2)
  94
  95 /* Control REG 3 */
  96 #define AD7879_TEMPMASK_BIT             (1<<15)
  97 #define AD7879_AUXVBATMASK_BIT          (1<<14)
  98 #define AD7879_INTMODE_BIT              (1<<13)
  99 #define AD7879_GPIOALERTMASK_BIT        (1<<12)
 100 #define AD7879_AUXLOW_BIT               (1<<11)
 101 #define AD7879_AUXHIGH_BIT              (1<<10)
 102 #define AD7879_TEMPLOW_BIT              (1<<9)
 103 #define AD7879_TEMPHIGH_BIT             (1<<8)
 104 #define AD7879_YPLUS_BIT                (1<<7)
 105 #define AD7879_XPLUS_BIT                (1<<6)
 106 #define AD7879_Z1_BIT                   (1<<5)
 107 #define AD7879_Z2_BIT                   (1<<4)
 108 #define AD7879_AUX_BIT                  (1<<3)
 109 #define AD7879_VBAT_BIT                 (1<<2)
 110 #define AD7879_TEMP_BIT                 (1<<1)
 111
 112 enum {
 113         AD7879_SEQ_XPOS  = 0,
 114         AD7879_SEQ_YPOS  = 1,
 115         AD7879_SEQ_Z1    = 2,
 116         AD7879_SEQ_Z2    = 3,
 117         AD7879_NR_SENSE  = 4,
 118 };
 119
 120 #define MAX_12BIT                       ((1<<12)-1)
 121 #define TS_PEN_UP_TIMEOUT               msecs_to_jiffies(50)
 122
 123 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
 124 #define AD7879_DEVID            0x7A
 125 typedef struct spi_device       bus_device;
 126 #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
 127 #define AD7879_DEVID            0x79
 128 typedef struct i2c_client       bus_device;
 129 #endif
 130
 131 struct ad7879 {
 132         bus_device              *bus;
 133         struct input_dev        *input;
 134         struct work_struct      work;
 135         struct timer_list       timer;
 136 #ifdef CONFIG_GPIOLIB
 137         struct gpio_chip        gc;
 138 #endif
 139         struct mutex            mutex;
 140         unsigned                disabled:1;     /* P: mutex */
 141
 142 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
 143         struct spi_message      msg;
 144         struct spi_transfer     xfer[AD7879_NR_SENSE + 1];
 145         u16                     cmd;
 146 #endif
 147         u16                     conversion_data[AD7879_NR_SENSE];
 148         char                    phys[32];
 149         u8                      first_conversion_delay;
 150         u8                      acquisition_time;
 151         u8                      averaging;
 152         u8                      pen_down_acc_interval;
 153         u8                      median;
 154         u16                     x_plate_ohms;
 155         u16                     pressure_max;
 156         u16                     cmd_crtl1;
 157         u16                     cmd_crtl2;
 158         u16                     cmd_crtl3;
 159 };
 160
 161 static int ad7879_read(bus_device *, u8);
 162 static int ad7879_write(bus_device *, u8, u16);
 163 static void ad7879_collect(struct ad7879 *);
 164
 165 static void ad7879_report(struct ad7879 *ts)
 166 {
 167         struct input_dev *input_dev = ts->input;
 168         unsigned Rt;
 169         u16 x, y, z1, z2;
 170
 171         x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
 172         y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
 173         z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
 174         z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
 175
 176         /*
 177          * The samples processed here are already preprocessed by the AD7879.
 178          * The preprocessing function consists of a median and an averaging filter.
 179          * The combination of these two techniques provides a robust solution,
 180          * discarding the spurious noise in the signal and keeping only the data of interest.
 181          * The size of both filters is programmable. (dev.platform_data, see linux/spi/ad7879.h)
 182          * Other user-programmable conversion controls include variable acquisition time,
 183          * and first conversion delay. Up to 16 averages can be taken per conversion.
 184          */
 185
 186         if (likely(x && z1)) {
 187                 /* compute touch pressure resistance using equation #1 */
 188                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 189                 Rt /= z1;
 190                 Rt = (Rt + 2047) >> 12;
 191
 192                 input_report_abs(input_dev, ABS_X, x);
 193                 input_report_abs(input_dev, ABS_Y, y);
 194                 input_report_abs(input_dev, ABS_PRESSURE, Rt);
 195                 input_sync(input_dev);
 196         }
 197 }
 198
 199 static void ad7879_work(struct work_struct *work)
 200 {
 201         struct ad7879 *ts = container_of(work, struct ad7879, work);
 202
 203         /* use keventd context to read the result registers */
 204         ad7879_collect(ts);
 205         ad7879_report(ts);
 206         mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 207 }
 208
 209 static void ad7879_ts_event_release(struct ad7879 *ts)
 210 {
 211         struct input_dev *input_dev = ts->input;
 212
 213         input_report_abs(input_dev, ABS_PRESSURE, 0);
 214         input_sync(input_dev);
 215 }
 216
 217 static void ad7879_timer(unsigned long handle)
 218 {
 219         struct ad7879 *ts = (void *)handle;
 220
 221         ad7879_ts_event_release(ts);
 222 }
 223
 224 static irqreturn_t ad7879_irq(int irq, void *handle)
 225 {
 226         struct ad7879 *ts = handle;
 227
 228         /* The repeated conversion sequencer controlled by TMR kicked off too fast.
 229          * We ignore the last and process the sample sequence currently in the queue.
 230          * It can't be older than 9.4ms
 231          */
 232
 233         if (!work_pending(&ts->work))
 234                 schedule_work(&ts->work);
 235
 236         return IRQ_HANDLED;
 237 }
 238
 239 static void ad7879_setup(struct ad7879 *ts)
 240 {
 241         ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
 242         ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
 243         ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
 244 }
 245
 246 static void ad7879_disable(struct ad7879 *ts)
 247 {
 248         mutex_lock(&ts->mutex);
 249
 250         if (!ts->disabled) {
 251
 252                 ts->disabled = 1;
 253                 disable_irq(ts->bus->irq);
 254
 255                 cancel_work_sync(&ts->work);
 256
 257                 if (del_timer_sync(&ts->timer))
 258                         ad7879_ts_event_release(ts);
 259
 260                 ad7879_write(ts->bus, AD7879_REG_CTRL2,
 261                              AD7879_PM(AD7879_PM_SHUTDOWN));
 262         }
 263
 264         mutex_unlock(&ts->mutex);
 265 }
 266
 267 static void ad7879_enable(struct ad7879 *ts)
 268 {
 269         mutex_lock(&ts->mutex);
 270
 271         if (ts->disabled) {
 272                 ad7879_setup(ts);
 273                 ts->disabled = 0;
 274                 enable_irq(ts->bus->irq);
 275         }
 276
 277         mutex_unlock(&ts->mutex);
 278 }
 279
 280 static ssize_t ad7879_disable_show(struct device *dev,
 281                                      struct device_attribute *attr, char *buf)
 282 {
 283         struct ad7879 *ts = dev_get_drvdata(dev);
 284
 285         return sprintf(buf, "%u\n", ts->disabled);
 286 }
 287
 288 static ssize_t ad7879_disable_store(struct device *dev,
 289                                      struct device_attribute *attr,
 290                                      const char *buf, size_t count)
 291 {
 292         struct ad7879 *ts = dev_get_drvdata(dev);
 293         unsigned long val;
 294         int error;
 295
 296         error = strict_strtoul(buf, 10, &val);
 297         if (error)
 298                 return error;
 299
 300         if (val)
 301                 ad7879_disable(ts);
 302         else
 303                 ad7879_enable(ts);
 304
 305         return count;
 306 }
 307
 308 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
 309
 310 static struct attribute *ad7879_attributes[] = {
 311         &dev_attr_disable.attr,
 312         NULL
 313 };
 314
 315 static const struct attribute_group ad7879_attr_group = {
 316         .attrs = ad7879_attributes,
 317 };
 318
 319 #ifdef CONFIG_GPIOLIB
 320 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
 321                                         unsigned gpio)
 322 {
 323         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 324         int err;
 325
 326         mutex_lock(&ts->mutex);
 327         ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
 328         err = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
 329         mutex_unlock(&ts->mutex);
 330
 331         return err;
 332 }
 333
 334 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
 335                                         unsigned gpio, int level)
 336 {
 337         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 338         int err;
 339
 340         mutex_lock(&ts->mutex);
 341         ts->cmd_crtl2 &= ~AD7879_GPIODIR;
 342         ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
 343         if (level)
 344                 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
 345         else
 346                 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
 347
 348         err = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
 349         mutex_unlock(&ts->mutex);
 350
 351         return err;
 352 }
 353
 354 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 355 {
 356         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 357         u16 val;
 358
 359         mutex_lock(&ts->mutex);
 360         val = ad7879_read(ts->bus, AD7879_REG_CTRL2);
 361         mutex_unlock(&ts->mutex);
 362
 363         return !!(val & AD7879_GPIO_DATA);
 364 }
 365
 366 static void ad7879_gpio_set_value(struct gpio_chip *chip,
 367                                   unsigned gpio, int value)
 368 {
 369         struct ad7879 *ts = container_of(chip, struct ad7879, gc);
 370
 371         mutex_lock(&ts->mutex);
 372         if (value)
 373                 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
 374         else
 375                 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
 376
 377         ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
 378         mutex_unlock(&ts->mutex);
 379 }
 380
 381 static int __devinit ad7879_gpio_add(struct device *dev)
 382 {
 383         struct ad7879 *ts = dev_get_drvdata(dev);
 384         struct ad7879_platform_data *pdata = dev->platform_data;
 385         int ret = 0;
 386
 387         if (pdata->gpio_export) {
 388                 ts->gc.direction_input = ad7879_gpio_direction_input;
 389                 ts->gc.direction_output = ad7879_gpio_direction_output;
 390                 ts->gc.get = ad7879_gpio_get_value;
 391                 ts->gc.set = ad7879_gpio_set_value;
 392                 ts->gc.can_sleep = 1;
 393                 ts->gc.base = pdata->gpio_base;
 394                 ts->gc.ngpio = 1;
 395                 ts->gc.label = "AD7879-GPIO";
 396                 ts->gc.owner = THIS_MODULE;
 397                 ts->gc.dev = dev;
 398
 399                 ret = gpiochip_add(&ts->gc);
 400                 if (ret)
 401                         dev_err(dev, "failed to register gpio %d\n",
 402                                 ts->gc.base);
 403         }
 404
 405         return ret;
 406 }
 407
 408 /*
 409  * We mark ad7879_gpio_remove inline so there is a chance the code
 410  * gets discarded when not needed. We can't do __devinit/__devexit
 411  * markup since it is used in both probe and remove methods.
 412  */
 413 static inline void ad7879_gpio_remove(struct device *dev)
 414 {
 415         struct ad7879 *ts = dev_get_drvdata(dev);
 416         struct ad7879_platform_data *pdata = dev->platform_data;
 417         int ret;
 418
 419         if (pdata->gpio_export) {
 420                 ret = gpiochip_remove(&ts->gc);
 421                 if (ret)
 422                         dev_err(dev, "failed to remove gpio %d\n",
 423                                 ts->gc.base);
 424         }
 425 }
 426 #else
 427 static inline int ad7879_gpio_add(struct device *dev)
 428 {
 429         return 0;
 430 }
 431
 432 static inline void ad7879_gpio_remove(struct device *dev)
 433 {
 434 }
 435 #endif
 436
 437 static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
 438 {
 439         struct input_dev *input_dev;
 440         struct ad7879_platform_data *pdata = bus->dev.platform_data;
 441         int err;
 442         u16 revid;
 443
 444         if (!bus->irq) {
 445                 dev_err(&bus->dev, "no IRQ?\n");
 446                 return -ENODEV;
 447         }
 448
 449         if (!pdata) {
 450                 dev_err(&bus->dev, "no platform data?\n");
 451                 return -ENODEV;
 452         }
 453
 454         input_dev = input_allocate_device();
 455         if (!input_dev)
 456                 return -ENOMEM;
 457
 458         ts->input = input_dev;
 459
 460         setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
 461         INIT_WORK(&ts->work, ad7879_work);
 462         mutex_init(&ts->mutex);
 463
 464         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 465         ts->pressure_max = pdata->pressure_max ? : ~0;
 466
 467         ts->first_conversion_delay = pdata->first_conversion_delay;
 468         ts->acquisition_time = pdata->acquisition_time;
 469         ts->averaging = pdata->averaging;
 470         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 471         ts->median = pdata->median;
 472
 473         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev));
 474
 475         input_dev->name = "AD7879 Touchscreen";
 476         input_dev->phys = ts->phys;
 477         input_dev->dev.parent = &bus->dev;
 478
 479         __set_bit(EV_ABS, input_dev->evbit);
 480         __set_bit(ABS_X, input_dev->absbit);
 481         __set_bit(ABS_Y, input_dev->absbit);
 482         __set_bit(ABS_PRESSURE, input_dev->absbit);
 483
 484         input_set_abs_params(input_dev, ABS_X,
 485                         pdata->x_min ? : 0,
 486                         pdata->x_max ? : MAX_12BIT,
 487                         0, 0);
 488         input_set_abs_params(input_dev, ABS_Y,
 489                         pdata->y_min ? : 0,
 490                         pdata->y_max ? : MAX_12BIT,
 491                         0, 0);
 492         input_set_abs_params(input_dev, ABS_PRESSURE,
 493                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 494
 495         err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET);
 496
 497         if (err < 0) {
 498                 dev_err(&bus->dev, "Failed to write %s\n", input_dev->name);
 499                 goto err_free_mem;
 500         }
 501
 502         revid = ad7879_read(bus, AD7879_REG_REVID);
 503
 504         if ((revid & 0xFF) != AD7879_DEVID) {
 505                 dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name);
 506                 err = -ENODEV;
 507                 goto err_free_mem;
 508         }
 509
 510         ts->cmd_crtl3 = AD7879_YPLUS_BIT |
 511                         AD7879_XPLUS_BIT |
 512                         AD7879_Z2_BIT |
 513                         AD7879_Z1_BIT |
 514                         AD7879_TEMPMASK_BIT |
 515                         AD7879_AUXVBATMASK_BIT |
 516                         AD7879_GPIOALERTMASK_BIT;
 517
 518         ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
 519                         AD7879_AVG(ts->averaging) |
 520                         AD7879_MFS(ts->median) |
 521                         AD7879_FCD(ts->first_conversion_delay);
 522
 523         ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
 524                         AD7879_ACQ(ts->acquisition_time) |
 525                         AD7879_TMR(ts->pen_down_acc_interval);
 526
 527         ad7879_setup(ts);
 528
 529         err = request_irq(bus->irq, ad7879_irq,
 530                           IRQF_TRIGGER_FALLING, bus->dev.driver->name, ts);
 531
 532         if (err) {
 533                 dev_err(&bus->dev, "irq %d busy?\n", bus->irq);
 534                 goto err_free_mem;
 535         }
 536
 537         err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group);
 538         if (err)
 539                 goto err_free_irq;
 540
 541         err = ad7879_gpio_add(&bus->dev);
 542         if (err)
 543                 goto err_remove_attr;
 544
 545         err = input_register_device(input_dev);
 546         if (err)
 547                 goto err_remove_gpio;
 548
 549         dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
 550                  revid >> 8, bus->irq);
 551
 552         return 0;
 553
 554 err_remove_gpio:
 555         ad7879_gpio_remove(&bus->dev);
 556 err_remove_attr:
 557         sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
 558 err_free_irq:
 559         free_irq(bus->irq, ts);
 560 err_free_mem:
 561         input_free_device(input_dev);
 562
 563         return err;
 564 }
 565
 566 static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts)
 567 {
 568         ad7879_gpio_remove(&bus->dev);
 569         ad7879_disable(ts);
 570         sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
 571         free_irq(ts->bus->irq, ts);
 572         input_unregister_device(ts->input);
 573         dev_dbg(&bus->dev, "unregistered touchscreen\n");
 574
 575         return 0;
 576 }
 577
 578 #ifdef CONFIG_PM
 579 static int ad7879_suspend(bus_device *bus, pm_message_t message)
 580 {
 581         struct ad7879 *ts = dev_get_drvdata(&bus->dev);
 582
 583         ad7879_disable(ts);
 584
 585         return 0;
 586 }
 587
 588 static int ad7879_resume(bus_device *bus)
 589 {
 590         struct ad7879 *ts = dev_get_drvdata(&bus->dev);
 591
 592         ad7879_enable(ts);
 593
 594         return 0;
 595 }
 596 #else
 597 #define ad7879_suspend NULL
 598 #define ad7879_resume  NULL
 599 #endif
 600
 601 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
 602 #define MAX_SPI_FREQ_HZ         5000000
 603 #define AD7879_CMD_MAGIC        0xE000
 604 #define AD7879_CMD_READ         (1 << 10)
 605 #define AD7879_WRITECMD(reg)    (AD7879_CMD_MAGIC | (reg & 0xF))
 606 #define AD7879_READCMD(reg)     (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF))
 607
 608 struct ser_req {
 609         u16                     command;
 610         u16                     data;
 611         struct spi_message      msg;
 612         struct spi_transfer     xfer[2];
 613 };
 614
 615 /*
 616  * ad7879_read/write are only used for initial setup and for sysfs controls.
 617  * The main traffic is done in ad7879_collect().
 618  */
 619
 620 static int ad7879_read(struct spi_device *spi, u8 reg)
 621 {
 622         struct ser_req *req;
 623         int status, ret;
 624
 625         req = kzalloc(sizeof *req, GFP_KERNEL);
 626         if (!req)
 627                 return -ENOMEM;
 628
 629         spi_message_init(&req->msg);
 630
 631         req->command = (u16) AD7879_READCMD(reg);
 632         req->xfer[0].tx_buf = &req->command;
 633         req->xfer[0].len = 2;
 634
 635         req->xfer[1].rx_buf = &req->data;
 636         req->xfer[1].len = 2;
 637
 638         spi_message_add_tail(&req->xfer[0], &req->msg);
 639         spi_message_add_tail(&req->xfer[1], &req->msg);
 640
 641         status = spi_sync(spi, &req->msg);
 642         ret = status ? : req->data;
 643
 644         kfree(req);
 645
 646         return ret;
 647 }
 648
 649 static int ad7879_write(struct spi_device *spi, u8 reg, u16 val)
 650 {
 651         struct ser_req *req;
 652         int status;
 653
 654         req = kzalloc(sizeof *req, GFP_KERNEL);
 655         if (!req)
 656                 return -ENOMEM;
 657
 658         spi_message_init(&req->msg);
 659
 660         req->command = (u16) AD7879_WRITECMD(reg);
 661         req->xfer[0].tx_buf = &req->command;
 662         req->xfer[0].len = 2;
 663
 664         req->data = val;
 665         req->xfer[1].tx_buf = &req->data;
 666         req->xfer[1].len = 2;
 667
 668         spi_message_add_tail(&req->xfer[0], &req->msg);
 669         spi_message_add_tail(&req->xfer[1], &req->msg);
 670
 671         status = spi_sync(spi, &req->msg);
 672
 673         kfree(req);
 674
 675         return status;
 676 }
 677
 678 static void ad7879_collect(struct ad7879 *ts)
 679 {
 680         int status = spi_sync(ts->bus, &ts->msg);
 681
 682         if (status)
 683                 dev_err(&ts->bus->dev, "spi_sync --> %d\n", status);
 684 }
 685
 686 static void ad7879_setup_ts_def_msg(struct ad7879 *ts)
 687 {
 688         struct spi_message *m;
 689         int i;
 690
 691         ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS);
 692
 693         m = &ts->msg;
 694         spi_message_init(m);
 695         ts->xfer[0].tx_buf = &ts->cmd;
 696         ts->xfer[0].len = 2;
 697
 698         spi_message_add_tail(&ts->xfer[0], m);
 699
 700         for (i = 0; i < AD7879_NR_SENSE; i++) {
 701                 ts->xfer[i + 1].rx_buf = &ts->conversion_data[i];
 702                 ts->xfer[i + 1].len = 2;
 703                 spi_message_add_tail(&ts->xfer[i + 1], m);
 704         }
 705 }
 706
 707 static int __devinit ad7879_probe(struct spi_device *spi)
 708 {
 709         struct ad7879 *ts;
 710         int error;
 711
 712         /* don't exceed max specified SPI CLK frequency */
 713         if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
 714                 dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
 715                 return -EINVAL;
 716         }
 717
 718         ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
 719         if (!ts)
 720                 return -ENOMEM;
 721
 722         dev_set_drvdata(&spi->dev, ts);
 723         ts->bus = spi;
 724
 725         ad7879_setup_ts_def_msg(ts);
 726
 727         error = ad7879_construct(spi, ts);
 728         if (error) {
 729                 dev_set_drvdata(&spi->dev, NULL);
 730                 kfree(ts);
 731         }
 732
 733         return error;
 734 }
 735
 736 static int __devexit ad7879_remove(struct spi_device *spi)
 737 {
 738         struct ad7879 *ts = dev_get_drvdata(&spi->dev);
 739
 740         ad7879_destroy(spi, ts);
 741         dev_set_drvdata(&spi->dev, NULL);
 742         kfree(ts);
 743
 744         return 0;
 745 }
 746
 747 static struct spi_driver ad7879_driver = {
 748         .driver = {
 749                 .name   = "ad7879",
 750                 .bus    = &spi_bus_type,
 751                 .owner  = THIS_MODULE,
 752         },
 753         .probe          = ad7879_probe,
 754         .remove         = __devexit_p(ad7879_remove),
 755         .suspend        = ad7879_suspend,
 756         .resume         = ad7879_resume,
 757 };
 758
 759 static int __init ad7879_init(void)
 760 {
 761         return spi_register_driver(&ad7879_driver);
 762 }
 763 module_init(ad7879_init);
 764
 765 static void __exit ad7879_exit(void)
 766 {
 767         spi_unregister_driver(&ad7879_driver);
 768 }
 769 module_exit(ad7879_exit);
 770
 771 #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
 772
 773 /* All registers are word-sized.
 774  * AD7879 uses a high-byte first convention.
 775  */
 776 static int ad7879_read(struct i2c_client *client, u8 reg)
 777 {
 778         return swab16(i2c_smbus_read_word_data(client, reg));
 779 }
 780
 781 static int ad7879_write(struct i2c_client *client, u8 reg, u16 val)
 782 {
 783         return i2c_smbus_write_word_data(client, reg, swab16(val));
 784 }
 785
 786 static void ad7879_collect(struct ad7879 *ts)
 787 {
 788         int i;
 789
 790         for (i = 0; i < AD7879_NR_SENSE; i++)
 791                 ts->conversion_data[i] = ad7879_read(ts->bus,
 792                                                      AD7879_REG_XPLUS + i);
 793 }
 794
 795 static int __devinit ad7879_probe(struct i2c_client *client,
 796                                         const struct i2c_device_id *id)
 797 {
 798         struct ad7879 *ts;
 799         int error;
 800
 801         if (!i2c_check_functionality(client->adapter,
 802                                         I2C_FUNC_SMBUS_WORD_DATA)) {
 803                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
 804                 return -EIO;
 805         }
 806
 807         ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
 808         if (!ts)
 809                 return -ENOMEM;
 810
 811         i2c_set_clientdata(client, ts);
 812         ts->bus = client;
 813
 814         error = ad7879_construct(client, ts);
 815         if (error) {
 816                 i2c_set_clientdata(client, NULL);
 817                 kfree(ts);
 818         }
 819
 820         return error;
 821 }
 822
 823 static int __devexit ad7879_remove(struct i2c_client *client)
 824 {
 825         struct ad7879 *ts = dev_get_drvdata(&client->dev);
 826
 827         ad7879_destroy(client, ts);
 828         i2c_set_clientdata(client, NULL);
 829         kfree(ts);
 830
 831         return 0;
 832 }
 833
 834 static const struct i2c_device_id ad7879_id[] = {
 835         { "ad7879", 0 },
 836         { "ad7889", 0 },
 837         { }
 838 };
 839 MODULE_DEVICE_TABLE(i2c, ad7879_id);
 840
 841 static struct i2c_driver ad7879_driver = {
 842         .driver = {
 843                 .name   = "ad7879",
 844                 .owner  = THIS_MODULE,
 845         },
 846         .probe          = ad7879_probe,
 847         .remove         = __devexit_p(ad7879_remove),
 848         .suspend        = ad7879_suspend,
 849         .resume         = ad7879_resume,
 850         .id_table       = ad7879_id,
 851 };
 852
 853 static int __init ad7879_init(void)
 854 {
 855         return i2c_add_driver(&ad7879_driver);
 856 }
 857 module_init(ad7879_init);
 858
 859 static void __exit ad7879_exit(void)
 860 {
 861         i2c_del_driver(&ad7879_driver);
 862 }
 863 module_exit(ad7879_exit);
 864 #endif
 865
 866 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 867 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
 868 MODULE_LICENSE("GPL");
 869 MODULE_ALIAS("spi:ad7879");