drivers/input/touchscreen/ad7877.c

   1 /*
   2  * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
   3  *
   4  * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
   5  * Based on:    ads7846.c
   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  */
  37
  38
  39 #include <linux/device.h>
  40 #include <linux/init.h>
  41 #include <linux/delay.h>
  42 #include <linux/input.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/slab.h>
  45 #include <linux/spi/spi.h>
  46 #include <linux/spi/ad7877.h>
  47 #include <asm/irq.h>
  48
  49 #define TS_PEN_UP_TIMEOUT       msecs_to_jiffies(50)
  50
  51 #define MAX_SPI_FREQ_HZ                 20000000
  52 #define MAX_12BIT                       ((1<<12)-1)
  53
  54 #define AD7877_REG_ZEROS                        0
  55 #define AD7877_REG_CTRL1                        1
  56 #define AD7877_REG_CTRL2                        2
  57 #define AD7877_REG_ALERT                        3
  58 #define AD7877_REG_AUX1HIGH                     4
  59 #define AD7877_REG_AUX1LOW                      5
  60 #define AD7877_REG_BAT1HIGH                     6
  61 #define AD7877_REG_BAT1LOW                      7
  62 #define AD7877_REG_BAT2HIGH                     8
  63 #define AD7877_REG_BAT2LOW                      9
  64 #define AD7877_REG_TEMP1HIGH                    10
  65 #define AD7877_REG_TEMP1LOW                     11
  66 #define AD7877_REG_SEQ0                         12
  67 #define AD7877_REG_SEQ1                         13
  68 #define AD7877_REG_DAC                          14
  69 #define AD7877_REG_NONE1                        15
  70 #define AD7877_REG_EXTWRITE                     15
  71 #define AD7877_REG_XPLUS                        16
  72 #define AD7877_REG_YPLUS                        17
  73 #define AD7877_REG_Z2                           18
  74 #define AD7877_REG_aux1                         19
  75 #define AD7877_REG_aux2                         20
  76 #define AD7877_REG_aux3                         21
  77 #define AD7877_REG_bat1                         22
  78 #define AD7877_REG_bat2                         23
  79 #define AD7877_REG_temp1                        24
  80 #define AD7877_REG_temp2                        25
  81 #define AD7877_REG_Z1                           26
  82 #define AD7877_REG_GPIOCTRL1                    27
  83 #define AD7877_REG_GPIOCTRL2                    28
  84 #define AD7877_REG_GPIODATA                     29
  85 #define AD7877_REG_NONE2                        30
  86 #define AD7877_REG_NONE3                        31
  87
  88 #define AD7877_SEQ_YPLUS_BIT                    (1<<11)
  89 #define AD7877_SEQ_XPLUS_BIT                    (1<<10)
  90 #define AD7877_SEQ_Z2_BIT                       (1<<9)
  91 #define AD7877_SEQ_AUX1_BIT                     (1<<8)
  92 #define AD7877_SEQ_AUX2_BIT                     (1<<7)
  93 #define AD7877_SEQ_AUX3_BIT                     (1<<6)
  94 #define AD7877_SEQ_BAT1_BIT                     (1<<5)
  95 #define AD7877_SEQ_BAT2_BIT                     (1<<4)
  96 #define AD7877_SEQ_TEMP1_BIT                    (1<<3)
  97 #define AD7877_SEQ_TEMP2_BIT                    (1<<2)
  98 #define AD7877_SEQ_Z1_BIT                       (1<<1)
  99
 100 enum {
 101         AD7877_SEQ_YPOS  = 0,
 102         AD7877_SEQ_XPOS  = 1,
 103         AD7877_SEQ_Z2    = 2,
 104         AD7877_SEQ_AUX1  = 3,
 105         AD7877_SEQ_AUX2  = 4,
 106         AD7877_SEQ_AUX3  = 5,
 107         AD7877_SEQ_BAT1  = 6,
 108         AD7877_SEQ_BAT2  = 7,
 109         AD7877_SEQ_TEMP1 = 8,
 110         AD7877_SEQ_TEMP2 = 9,
 111         AD7877_SEQ_Z1    = 10,
 112         AD7877_NR_SENSE  = 11,
 113 };
 114
 115 /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
 116 #define AD7877_DAC_CONF                 0x1
 117
 118 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
 119 #define AD7877_EXTW_GPIO_3_CONF         0x1C4
 120 #define AD7877_EXTW_GPIO_DATA           0x200
 121
 122 /* Control REG 2 */
 123 #define AD7877_TMR(x)                   ((x & 0x3) << 0)
 124 #define AD7877_REF(x)                   ((x & 0x1) << 2)
 125 #define AD7877_POL(x)                   ((x & 0x1) << 3)
 126 #define AD7877_FCD(x)                   ((x & 0x3) << 4)
 127 #define AD7877_PM(x)                    ((x & 0x3) << 6)
 128 #define AD7877_ACQ(x)                   ((x & 0x3) << 8)
 129 #define AD7877_AVG(x)                   ((x & 0x3) << 10)
 130
 131 /* Control REG 1 */
 132 #define AD7877_SER                      (1 << 11)       /* non-differential */
 133 #define AD7877_DFR                      (0 << 11)       /* differential */
 134
 135 #define AD7877_MODE_NOC  (0)    /* Do not convert */
 136 #define AD7877_MODE_SCC  (1)    /* Single channel conversion */
 137 #define AD7877_MODE_SEQ0 (2)    /* Sequence 0 in Slave Mode */
 138 #define AD7877_MODE_SEQ1 (3)    /* Sequence 1 in Master Mode */
 139
 140 #define AD7877_CHANADD(x)               ((x&0xF)<<7)
 141 #define AD7877_READADD(x)               ((x)<<2)
 142 #define AD7877_WRITEADD(x)              ((x)<<12)
 143
 144 #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
 145                 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
 146                 AD7877_READADD(AD7877_REG_ ## x))
 147
 148 #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
 149                 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
 150
 151 /*
 152  * Non-touchscreen sensors only use single-ended conversions.
 153  */
 154
 155 struct ser_req {
 156         u16                     reset;
 157         u16                     ref_on;
 158         u16                     command;
 159         u16                     sample;
 160         struct spi_message      msg;
 161         struct spi_transfer     xfer[6];
 162 };
 163
 164 struct ad7877 {
 165         struct input_dev        *input;
 166         char                    phys[32];
 167
 168         struct spi_device       *spi;
 169         u16                     model;
 170         u16                     vref_delay_usecs;
 171         u16                     x_plate_ohms;
 172         u16                     pressure_max;
 173
 174         u16                     cmd_crtl1;
 175         u16                     cmd_crtl2;
 176         u16                     cmd_dummy;
 177         u16                     dac;
 178
 179         u8                      stopacq_polarity;
 180         u8                      first_conversion_delay;
 181         u8                      acquisition_time;
 182         u8                      averaging;
 183         u8                      pen_down_acc_interval;
 184
 185         u16                     conversion_data[AD7877_NR_SENSE];
 186
 187         struct spi_transfer     xfer[AD7877_NR_SENSE + 2];
 188         struct spi_message      msg;
 189
 190         struct mutex            mutex;
 191         unsigned                disabled:1;     /* P: mutex */
 192         unsigned                gpio3:1;        /* P: mutex */
 193         unsigned                gpio4:1;        /* P: mutex */
 194
 195         spinlock_t              lock;
 196         struct timer_list       timer;          /* P: lock */
 197         unsigned                pending:1;      /* P: lock */
 198 };
 199
 200 static int gpio3;
 201 module_param(gpio3, int, 0);
 202 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
 203
 204 /*
 205  * ad7877_read/write are only used for initial setup and for sysfs controls.
 206  * The main traffic is done using spi_async() in the interrupt handler.
 207  */
 208
 209 static int ad7877_read(struct spi_device *spi, u16 reg)
 210 {
 211         struct ser_req *req;
 212         int status, ret;
 213
 214         req = kzalloc(sizeof *req, GFP_KERNEL);
 215         if (!req)
 216                 return -ENOMEM;
 217
 218         spi_message_init(&req->msg);
 219
 220         req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
 221                         AD7877_READADD(reg));
 222         req->xfer[0].tx_buf = &req->command;
 223         req->xfer[0].len = 2;
 224
 225         req->xfer[1].rx_buf = &req->sample;
 226         req->xfer[1].len = 2;
 227
 228         spi_message_add_tail(&req->xfer[0], &req->msg);
 229         spi_message_add_tail(&req->xfer[1], &req->msg);
 230
 231         status = spi_sync(spi, &req->msg);
 232         ret = status ? : req->sample;
 233
 234         kfree(req);
 235
 236         return ret;
 237 }
 238
 239 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
 240 {
 241         struct ser_req *req;
 242         int status;
 243
 244         req = kzalloc(sizeof *req, GFP_KERNEL);
 245         if (!req)
 246                 return -ENOMEM;
 247
 248         spi_message_init(&req->msg);
 249
 250         req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
 251         req->xfer[0].tx_buf = &req->command;
 252         req->xfer[0].len = 2;
 253
 254         spi_message_add_tail(&req->xfer[0], &req->msg);
 255
 256         status = spi_sync(spi, &req->msg);
 257
 258         kfree(req);
 259
 260         return status;
 261 }
 262
 263 static int ad7877_read_adc(struct spi_device *spi, unsigned command)
 264 {
 265         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 266         struct ser_req *req;
 267         int status;
 268         int sample;
 269         int i;
 270
 271         req = kzalloc(sizeof *req, GFP_KERNEL);
 272         if (!req)
 273                 return -ENOMEM;
 274
 275         spi_message_init(&req->msg);
 276
 277         /* activate reference, so it has time to settle; */
 278         req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 279                          AD7877_POL(ts->stopacq_polarity) |
 280                          AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
 281                          AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
 282
 283         req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
 284
 285         req->command = (u16) command;
 286
 287         req->xfer[0].tx_buf = &req->reset;
 288         req->xfer[0].len = 2;
 289
 290         req->xfer[1].tx_buf = &req->ref_on;
 291         req->xfer[1].len = 2;
 292         req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 293
 294         req->xfer[2].tx_buf = &req->command;
 295         req->xfer[2].len = 2;
 296         req->xfer[2].delay_usecs = ts->vref_delay_usecs;
 297
 298         req->xfer[3].rx_buf = &req->sample;
 299         req->xfer[3].len = 2;
 300
 301         req->xfer[4].tx_buf = &ts->cmd_crtl2;   /*REF OFF*/
 302         req->xfer[4].len = 2;
 303
 304         req->xfer[5].tx_buf = &ts->cmd_crtl1;   /*DEFAULT*/
 305         req->xfer[5].len = 2;
 306
 307         /* group all the transfers together, so we can't interfere with
 308          * reading touchscreen state; disable penirq while sampling
 309          */
 310         for (i = 0; i < 6; i++)
 311                 spi_message_add_tail(&req->xfer[i], &req->msg);
 312
 313         status = spi_sync(spi, &req->msg);
 314         sample = req->sample;
 315
 316         kfree(req);
 317
 318         return status ? : sample;
 319 }
 320
 321 static void ad7877_rx(struct ad7877 *ts)
 322 {
 323         struct input_dev *input_dev = ts->input;
 324         unsigned Rt;
 325         u16 x, y, z1, z2;
 326
 327         x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
 328         y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
 329         z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
 330         z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
 331
 332         /*
 333          * The samples processed here are already preprocessed by the AD7877.
 334          * The preprocessing function consists of an averaging filter.
 335          * The combination of 'first conversion delay' and averaging provides a robust solution,
 336          * discarding the spurious noise in the signal and keeping only the data of interest.
 337          * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
 338          * Other user-programmable conversion controls include variable acquisition time,
 339          * and first conversion delay. Up to 16 averages can be taken per conversion.
 340          */
 341
 342         if (likely(x && z1)) {
 343                 /* compute touch pressure resistance using equation #1 */
 344                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 345                 Rt /= z1;
 346                 Rt = (Rt + 2047) >> 12;
 347
 348                 input_report_abs(input_dev, ABS_X, x);
 349                 input_report_abs(input_dev, ABS_Y, y);
 350                 input_report_abs(input_dev, ABS_PRESSURE, Rt);
 351                 input_sync(input_dev);
 352         }
 353 }
 354
 355 static inline void ad7877_ts_event_release(struct ad7877 *ts)
 356 {
 357         struct input_dev *input_dev = ts->input;
 358
 359         input_report_abs(input_dev, ABS_PRESSURE, 0);
 360         input_sync(input_dev);
 361 }
 362
 363 static void ad7877_timer(unsigned long handle)
 364 {
 365         struct ad7877 *ts = (void *)handle;
 366
 367         ad7877_ts_event_release(ts);
 368 }
 369
 370 static irqreturn_t ad7877_irq(int irq, void *handle)
 371 {
 372         struct ad7877 *ts = handle;
 373         unsigned long flags;
 374         int status;
 375
 376         /*
 377          * The repeated conversion sequencer controlled by TMR kicked off
 378          * too fast. We ignore the last and process the sample sequence
 379          * currently in the queue. It can't be older than 9.4ms, and we
 380          * need to avoid that ts->msg doesn't get issued twice while in work.
 381          */
 382
 383         spin_lock_irqsave(&ts->lock, flags);
 384         if (!ts->pending) {
 385                 ts->pending = 1;
 386
 387                 status = spi_async(ts->spi, &ts->msg);
 388                 if (status)
 389                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", status);
 390         }
 391         spin_unlock_irqrestore(&ts->lock, flags);
 392
 393         return IRQ_HANDLED;
 394 }
 395
 396 static void ad7877_callback(void *_ts)
 397 {
 398         struct ad7877 *ts = _ts;
 399
 400         spin_lock_irq(&ts->lock);
 401
 402         ad7877_rx(ts);
 403         ts->pending = 0;
 404         mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 405
 406         spin_unlock_irq(&ts->lock);
 407 }
 408
 409 static void ad7877_disable(struct ad7877 *ts)
 410 {
 411         mutex_lock(&ts->mutex);
 412
 413         if (!ts->disabled) {
 414                 ts->disabled = 1;
 415                 disable_irq(ts->spi->irq);
 416
 417                 /* Wait for spi_async callback */
 418                 while (ts->pending)
 419                         msleep(1);
 420
 421                 if (del_timer_sync(&ts->timer))
 422                         ad7877_ts_event_release(ts);
 423         }
 424
 425         /* we know the chip's in lowpower mode since we always
 426          * leave it that way after every request
 427          */
 428
 429         mutex_unlock(&ts->mutex);
 430 }
 431
 432 static void ad7877_enable(struct ad7877 *ts)
 433 {
 434         mutex_lock(&ts->mutex);
 435
 436         if (ts->disabled) {
 437                 ts->disabled = 0;
 438                 enable_irq(ts->spi->irq);
 439         }
 440
 441         mutex_unlock(&ts->mutex);
 442 }
 443
 444 #define SHOW(name) static ssize_t \
 445 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 446 { \
 447         struct ad7877   *ts = dev_get_drvdata(dev); \
 448         ssize_t v = ad7877_read_adc(ts->spi, \
 449                         AD7877_READ_CHAN(name)); \
 450         if (v < 0) \
 451                 return v; \
 452         return sprintf(buf, "%u\n", (unsigned) v); \
 453 } \
 454 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 455
 456 SHOW(aux1)
 457 SHOW(aux2)
 458 SHOW(aux3)
 459 SHOW(bat1)
 460 SHOW(bat2)
 461 SHOW(temp1)
 462 SHOW(temp2)
 463
 464 static ssize_t ad7877_disable_show(struct device *dev,
 465                                      struct device_attribute *attr, char *buf)
 466 {
 467         struct ad7877   *ts = dev_get_drvdata(dev);
 468
 469         return sprintf(buf, "%u\n", ts->disabled);
 470 }
 471
 472 static ssize_t ad7877_disable_store(struct device *dev,
 473                                      struct device_attribute *attr,
 474                                      const char *buf, size_t count)
 475 {
 476         struct ad7877 *ts = dev_get_drvdata(dev);
 477         unsigned long val;
 478         int error;
 479
 480         error = strict_strtoul(buf, 10, &val);
 481         if (error)
 482                 return error;
 483
 484         if (val)
 485                 ad7877_disable(ts);
 486         else
 487                 ad7877_enable(ts);
 488
 489         return count;
 490 }
 491
 492 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
 493
 494 static ssize_t ad7877_dac_show(struct device *dev,
 495                                      struct device_attribute *attr, char *buf)
 496 {
 497         struct ad7877   *ts = dev_get_drvdata(dev);
 498
 499         return sprintf(buf, "%u\n", ts->dac);
 500 }
 501
 502 static ssize_t ad7877_dac_store(struct device *dev,
 503                                      struct device_attribute *attr,
 504                                      const char *buf, size_t count)
 505 {
 506         struct ad7877 *ts = dev_get_drvdata(dev);
 507         unsigned long val;
 508         int error;
 509
 510         error = strict_strtoul(buf, 10, &val);
 511         if (error)
 512                 return error;
 513
 514         mutex_lock(&ts->mutex);
 515         ts->dac = val & 0xFF;
 516         ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
 517         mutex_unlock(&ts->mutex);
 518
 519         return count;
 520 }
 521
 522 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
 523
 524 static ssize_t ad7877_gpio3_show(struct device *dev,
 525                                      struct device_attribute *attr, char *buf)
 526 {
 527         struct ad7877   *ts = dev_get_drvdata(dev);
 528
 529         return sprintf(buf, "%u\n", ts->gpio3);
 530 }
 531
 532 static ssize_t ad7877_gpio3_store(struct device *dev,
 533                                      struct device_attribute *attr,
 534                                      const char *buf, size_t count)
 535 {
 536         struct ad7877 *ts = dev_get_drvdata(dev);
 537         unsigned long val;
 538         int error;
 539
 540         error = strict_strtoul(buf, 10, &val);
 541         if (error)
 542                 return error;
 543
 544         mutex_lock(&ts->mutex);
 545         ts->gpio3 = !!val;
 546         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 547                  (ts->gpio4 << 4) | (ts->gpio3 << 5));
 548         mutex_unlock(&ts->mutex);
 549
 550         return count;
 551 }
 552
 553 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
 554
 555 static ssize_t ad7877_gpio4_show(struct device *dev,
 556                                      struct device_attribute *attr, char *buf)
 557 {
 558         struct ad7877   *ts = dev_get_drvdata(dev);
 559
 560         return sprintf(buf, "%u\n", ts->gpio4);
 561 }
 562
 563 static ssize_t ad7877_gpio4_store(struct device *dev,
 564                                      struct device_attribute *attr,
 565                                      const char *buf, size_t count)
 566 {
 567         struct ad7877 *ts = dev_get_drvdata(dev);
 568         unsigned long val;
 569         int error;
 570
 571         error = strict_strtoul(buf, 10, &val);
 572         if (error)
 573                 return error;
 574
 575         mutex_lock(&ts->mutex);
 576         ts->gpio4 = !!val;
 577         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 578                      (ts->gpio4 << 4) | (ts->gpio3 << 5));
 579         mutex_unlock(&ts->mutex);
 580
 581         return count;
 582 }
 583
 584 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
 585
 586 static struct attribute *ad7877_attributes[] = {
 587         &dev_attr_temp1.attr,
 588         &dev_attr_temp2.attr,
 589         &dev_attr_aux1.attr,
 590         &dev_attr_aux2.attr,
 591         &dev_attr_bat1.attr,
 592         &dev_attr_bat2.attr,
 593         &dev_attr_disable.attr,
 594         &dev_attr_dac.attr,
 595         &dev_attr_gpio4.attr,
 596         NULL
 597 };
 598
 599 static const struct attribute_group ad7877_attr_group = {
 600         .attrs = ad7877_attributes,
 601 };
 602
 603 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
 604 {
 605         struct spi_message *m;
 606         int i;
 607
 608         ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 609                         AD7877_POL(ts->stopacq_polarity) |
 610                         AD7877_AVG(ts->averaging) | AD7877_PM(1) |
 611                         AD7877_TMR(ts->pen_down_acc_interval) |
 612                         AD7877_ACQ(ts->acquisition_time) |
 613                         AD7877_FCD(ts->first_conversion_delay);
 614
 615         ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
 616
 617         ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
 618                         AD7877_READADD(AD7877_REG_XPLUS-1) |
 619                         AD7877_MODE_SEQ1 | AD7877_DFR;
 620
 621         ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
 622
 623         ts->cmd_dummy = 0;
 624
 625         m = &ts->msg;
 626
 627         spi_message_init(m);
 628
 629         m->complete = ad7877_callback;
 630         m->context = ts;
 631
 632         ts->xfer[0].tx_buf = &ts->cmd_crtl1;
 633         ts->xfer[0].len = 2;
 634
 635         spi_message_add_tail(&ts->xfer[0], m);
 636
 637         ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
 638         ts->xfer[1].len = 2;
 639
 640         spi_message_add_tail(&ts->xfer[1], m);
 641
 642         for (i = 0; i < 11; i++) {
 643                 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
 644                 ts->xfer[i + 2].len = 2;
 645                 spi_message_add_tail(&ts->xfer[i + 2], m);
 646         }
 647 }
 648
 649 static int __devinit ad7877_probe(struct spi_device *spi)
 650 {
 651         struct ad7877                   *ts;
 652         struct input_dev                *input_dev;
 653         struct ad7877_platform_data     *pdata = spi->dev.platform_data;
 654         int                             err;
 655         u16                             verify;
 656
 657         if (!spi->irq) {
 658                 dev_dbg(&spi->dev, "no IRQ?\n");
 659                 return -ENODEV;
 660         }
 661
 662         if (!pdata) {
 663                 dev_dbg(&spi->dev, "no platform data?\n");
 664                 return -ENODEV;
 665         }
 666
 667         /* don't exceed max specified SPI CLK frequency */
 668         if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
 669                 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
 670                 return -EINVAL;
 671         }
 672
 673         ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
 674         input_dev = input_allocate_device();
 675         if (!ts || !input_dev) {
 676                 err = -ENOMEM;
 677                 goto err_free_mem;
 678         }
 679
 680         dev_set_drvdata(&spi->dev, ts);
 681         ts->spi = spi;
 682         ts->input = input_dev;
 683
 684         setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
 685         mutex_init(&ts->mutex);
 686         spin_lock_init(&ts->lock);
 687
 688         ts->model = pdata->model ? : 7877;
 689         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 690         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 691         ts->pressure_max = pdata->pressure_max ? : ~0;
 692
 693         ts->stopacq_polarity = pdata->stopacq_polarity;
 694         ts->first_conversion_delay = pdata->first_conversion_delay;
 695         ts->acquisition_time = pdata->acquisition_time;
 696         ts->averaging = pdata->averaging;
 697         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 698
 699         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 700
 701         input_dev->name = "AD7877 Touchscreen";
 702         input_dev->phys = ts->phys;
 703         input_dev->dev.parent = &spi->dev;
 704
 705         __set_bit(EV_ABS, input_dev->evbit);
 706         __set_bit(ABS_X, input_dev->absbit);
 707         __set_bit(ABS_Y, input_dev->absbit);
 708         __set_bit(ABS_PRESSURE, input_dev->absbit);
 709
 710         input_set_abs_params(input_dev, ABS_X,
 711                         pdata->x_min ? : 0,
 712                         pdata->x_max ? : MAX_12BIT,
 713                         0, 0);
 714         input_set_abs_params(input_dev, ABS_Y,
 715                         pdata->y_min ? : 0,
 716                         pdata->y_max ? : MAX_12BIT,
 717                         0, 0);
 718         input_set_abs_params(input_dev, ABS_PRESSURE,
 719                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 720
 721         ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
 722
 723         verify = ad7877_read(spi, AD7877_REG_SEQ1);
 724
 725         if (verify != AD7877_MM_SEQUENCE){
 726                 dev_err(&spi->dev, "%s: Failed to probe %s\n",
 727                         dev_name(&spi->dev), input_dev->name);
 728                 err = -ENODEV;
 729                 goto err_free_mem;
 730         }
 731
 732         if (gpio3)
 733                 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
 734
 735         ad7877_setup_ts_def_msg(spi, ts);
 736
 737         /* Request AD7877 /DAV GPIO interrupt */
 738
 739         err = request_irq(spi->irq, ad7877_irq, IRQF_TRIGGER_FALLING,
 740                         spi->dev.driver->name, ts);
 741         if (err) {
 742                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 743                 goto err_free_mem;
 744         }
 745
 746         err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
 747         if (err)
 748                 goto err_free_irq;
 749
 750         err = device_create_file(&spi->dev,
 751                                  gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 752         if (err)
 753                 goto err_remove_attr_group;
 754
 755         err = input_register_device(input_dev);
 756         if (err)
 757                 goto err_remove_attr;
 758
 759         return 0;
 760
 761 err_remove_attr:
 762         device_remove_file(&spi->dev,
 763                            gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 764 err_remove_attr_group:
 765         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 766 err_free_irq:
 767         free_irq(spi->irq, ts);
 768 err_free_mem:
 769         input_free_device(input_dev);
 770         kfree(ts);
 771         dev_set_drvdata(&spi->dev, NULL);
 772         return err;
 773 }
 774
 775 static int __devexit ad7877_remove(struct spi_device *spi)
 776 {
 777         struct ad7877           *ts = dev_get_drvdata(&spi->dev);
 778
 779         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 780         device_remove_file(&spi->dev,
 781                            gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 782
 783         ad7877_disable(ts);
 784         free_irq(ts->spi->irq, ts);
 785
 786         input_unregister_device(ts->input);
 787         kfree(ts);
 788
 789         dev_dbg(&spi->dev, "unregistered touchscreen\n");
 790         dev_set_drvdata(&spi->dev, NULL);
 791
 792         return 0;
 793 }
 794
 795 #ifdef CONFIG_PM
 796 static int ad7877_suspend(struct spi_device *spi, pm_message_t message)
 797 {
 798         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 799
 800         ad7877_disable(ts);
 801
 802         return 0;
 803 }
 804
 805 static int ad7877_resume(struct spi_device *spi)
 806 {
 807         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 808
 809         ad7877_enable(ts);
 810
 811         return 0;
 812 }
 813 #else
 814 #define ad7877_suspend NULL
 815 #define ad7877_resume  NULL
 816 #endif
 817
 818 static struct spi_driver ad7877_driver = {
 819         .driver = {
 820                 .name   = "ad7877",
 821                 .bus    = &spi_bus_type,
 822                 .owner  = THIS_MODULE,
 823         },
 824         .probe          = ad7877_probe,
 825         .remove         = __devexit_p(ad7877_remove),
 826         .suspend        = ad7877_suspend,
 827         .resume         = ad7877_resume,
 828 };
 829
 830 static int __init ad7877_init(void)
 831 {
 832         return spi_register_driver(&ad7877_driver);
 833 }
 834 module_init(ad7877_init);
 835
 836 static void __exit ad7877_exit(void)
 837 {
 838         spi_unregister_driver(&ad7877_driver);
 839 }
 840 module_exit(ad7877_exit);
 841
 842 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 843 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
 844 MODULE_LICENSE("GPL");
 845 MODULE_ALIAS("spi:ad7877");