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/delay.h>
  41 #include <linux/input.h>
  42 #include <linux/interrupt.h>
  43 #include <linux/pm.h>
  44 #include <linux/slab.h>
  45 #include <linux/spi/spi.h>
  46 #include <linux/spi/ad7877.h>
  47 #include <linux/module.h>
  48 #include <asm/irq.h>
  49
  50 #define TS_PEN_UP_TIMEOUT       msecs_to_jiffies(100)
  51
  52 #define MAX_SPI_FREQ_HZ                 20000000
  53 #define MAX_12BIT                       ((1<<12)-1)
  54
  55 #define AD7877_REG_ZEROS                        0
  56 #define AD7877_REG_CTRL1                        1
  57 #define AD7877_REG_CTRL2                        2
  58 #define AD7877_REG_ALERT                        3
  59 #define AD7877_REG_AUX1HIGH                     4
  60 #define AD7877_REG_AUX1LOW                      5
  61 #define AD7877_REG_BAT1HIGH                     6
  62 #define AD7877_REG_BAT1LOW                      7
  63 #define AD7877_REG_BAT2HIGH                     8
  64 #define AD7877_REG_BAT2LOW                      9
  65 #define AD7877_REG_TEMP1HIGH                    10
  66 #define AD7877_REG_TEMP1LOW                     11
  67 #define AD7877_REG_SEQ0                         12
  68 #define AD7877_REG_SEQ1                         13
  69 #define AD7877_REG_DAC                          14
  70 #define AD7877_REG_NONE1                        15
  71 #define AD7877_REG_EXTWRITE                     15
  72 #define AD7877_REG_XPLUS                        16
  73 #define AD7877_REG_YPLUS                        17
  74 #define AD7877_REG_Z2                           18
  75 #define AD7877_REG_aux1                         19
  76 #define AD7877_REG_aux2                         20
  77 #define AD7877_REG_aux3                         21
  78 #define AD7877_REG_bat1                         22
  79 #define AD7877_REG_bat2                         23
  80 #define AD7877_REG_temp1                        24
  81 #define AD7877_REG_temp2                        25
  82 #define AD7877_REG_Z1                           26
  83 #define AD7877_REG_GPIOCTRL1                    27
  84 #define AD7877_REG_GPIOCTRL2                    28
  85 #define AD7877_REG_GPIODATA                     29
  86 #define AD7877_REG_NONE2                        30
  87 #define AD7877_REG_NONE3                        31
  88
  89 #define AD7877_SEQ_YPLUS_BIT                    (1<<11)
  90 #define AD7877_SEQ_XPLUS_BIT                    (1<<10)
  91 #define AD7877_SEQ_Z2_BIT                       (1<<9)
  92 #define AD7877_SEQ_AUX1_BIT                     (1<<8)
  93 #define AD7877_SEQ_AUX2_BIT                     (1<<7)
  94 #define AD7877_SEQ_AUX3_BIT                     (1<<6)
  95 #define AD7877_SEQ_BAT1_BIT                     (1<<5)
  96 #define AD7877_SEQ_BAT2_BIT                     (1<<4)
  97 #define AD7877_SEQ_TEMP1_BIT                    (1<<3)
  98 #define AD7877_SEQ_TEMP2_BIT                    (1<<2)
  99 #define AD7877_SEQ_Z1_BIT                       (1<<1)
 100
 101 enum {
 102         AD7877_SEQ_YPOS  = 0,
 103         AD7877_SEQ_XPOS  = 1,
 104         AD7877_SEQ_Z2    = 2,
 105         AD7877_SEQ_AUX1  = 3,
 106         AD7877_SEQ_AUX2  = 4,
 107         AD7877_SEQ_AUX3  = 5,
 108         AD7877_SEQ_BAT1  = 6,
 109         AD7877_SEQ_BAT2  = 7,
 110         AD7877_SEQ_TEMP1 = 8,
 111         AD7877_SEQ_TEMP2 = 9,
 112         AD7877_SEQ_Z1    = 10,
 113         AD7877_NR_SENSE  = 11,
 114 };
 115
 116 /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
 117 #define AD7877_DAC_CONF                 0x1
 118
 119 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
 120 #define AD7877_EXTW_GPIO_3_CONF         0x1C4
 121 #define AD7877_EXTW_GPIO_DATA           0x200
 122
 123 /* Control REG 2 */
 124 #define AD7877_TMR(x)                   ((x & 0x3) << 0)
 125 #define AD7877_REF(x)                   ((x & 0x1) << 2)
 126 #define AD7877_POL(x)                   ((x & 0x1) << 3)
 127 #define AD7877_FCD(x)                   ((x & 0x3) << 4)
 128 #define AD7877_PM(x)                    ((x & 0x3) << 6)
 129 #define AD7877_ACQ(x)                   ((x & 0x3) << 8)
 130 #define AD7877_AVG(x)                   ((x & 0x3) << 10)
 131
 132 /* Control REG 1 */
 133 #define AD7877_SER                      (1 << 11)       /* non-differential */
 134 #define AD7877_DFR                      (0 << 11)       /* differential */
 135
 136 #define AD7877_MODE_NOC  (0)    /* Do not convert */
 137 #define AD7877_MODE_SCC  (1)    /* Single channel conversion */
 138 #define AD7877_MODE_SEQ0 (2)    /* Sequence 0 in Slave Mode */
 139 #define AD7877_MODE_SEQ1 (3)    /* Sequence 1 in Master Mode */
 140
 141 #define AD7877_CHANADD(x)               ((x&0xF)<<7)
 142 #define AD7877_READADD(x)               ((x)<<2)
 143 #define AD7877_WRITEADD(x)              ((x)<<12)
 144
 145 #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
 146                 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
 147                 AD7877_READADD(AD7877_REG_ ## x))
 148
 149 #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
 150                 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
 151
 152 /*
 153  * Non-touchscreen sensors only use single-ended conversions.
 154  */
 155
 156 struct ser_req {
 157         u16                     reset;
 158         u16                     ref_on;
 159         u16                     command;
 160         struct spi_message      msg;
 161         struct spi_transfer     xfer[6];
 162
 163         /*
 164          * DMA (thus cache coherency maintenance) requires the
 165          * transfer buffers to live in their own cache lines.
 166          */
 167         u16 sample ____cacheline_aligned;
 168 };
 169
 170 struct ad7877 {
 171         struct input_dev        *input;
 172         char                    phys[32];
 173
 174         struct spi_device       *spi;
 175         u16                     model;
 176         u16                     vref_delay_usecs;
 177         u16                     x_plate_ohms;
 178         u16                     pressure_max;
 179
 180         u16                     cmd_crtl1;
 181         u16                     cmd_crtl2;
 182         u16                     cmd_dummy;
 183         u16                     dac;
 184
 185         u8                      stopacq_polarity;
 186         u8                      first_conversion_delay;
 187         u8                      acquisition_time;
 188         u8                      averaging;
 189         u8                      pen_down_acc_interval;
 190
 191         struct spi_transfer     xfer[AD7877_NR_SENSE + 2];
 192         struct spi_message      msg;
 193
 194         struct mutex            mutex;
 195         bool                    disabled;       /* P: mutex */
 196         bool                    gpio3;          /* P: mutex */
 197         bool                    gpio4;          /* P: mutex */
 198
 199         spinlock_t              lock;
 200         struct timer_list       timer;          /* P: lock */
 201
 202         /*
 203          * DMA (thus cache coherency maintenance) requires the
 204          * transfer buffers to live in their own cache lines.
 205          */
 206         u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
 207 };
 208
 209 static bool gpio3;
 210 module_param(gpio3, bool, 0);
 211 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
 212
 213 static int ad7877_read(struct spi_device *spi, u16 reg)
 214 {
 215         struct ser_req *req;
 216         int status, ret;
 217
 218         req = kzalloc(sizeof *req, GFP_KERNEL);
 219         if (!req)
 220                 return -ENOMEM;
 221
 222         spi_message_init(&req->msg);
 223
 224         req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
 225                         AD7877_READADD(reg));
 226         req->xfer[0].tx_buf = &req->command;
 227         req->xfer[0].len = 2;
 228         req->xfer[0].cs_change = 1;
 229
 230         req->xfer[1].rx_buf = &req->sample;
 231         req->xfer[1].len = 2;
 232
 233         spi_message_add_tail(&req->xfer[0], &req->msg);
 234         spi_message_add_tail(&req->xfer[1], &req->msg);
 235
 236         status = spi_sync(spi, &req->msg);
 237         ret = status ? : req->sample;
 238
 239         kfree(req);
 240
 241         return ret;
 242 }
 243
 244 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
 245 {
 246         struct ser_req *req;
 247         int status;
 248
 249         req = kzalloc(sizeof *req, GFP_KERNEL);
 250         if (!req)
 251                 return -ENOMEM;
 252
 253         spi_message_init(&req->msg);
 254
 255         req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
 256         req->xfer[0].tx_buf = &req->command;
 257         req->xfer[0].len = 2;
 258
 259         spi_message_add_tail(&req->xfer[0], &req->msg);
 260
 261         status = spi_sync(spi, &req->msg);
 262
 263         kfree(req);
 264
 265         return status;
 266 }
 267
 268 static int ad7877_read_adc(struct spi_device *spi, unsigned command)
 269 {
 270         struct ad7877 *ts = spi_get_drvdata(spi);
 271         struct ser_req *req;
 272         int status;
 273         int sample;
 274         int i;
 275
 276         req = kzalloc(sizeof *req, GFP_KERNEL);
 277         if (!req)
 278                 return -ENOMEM;
 279
 280         spi_message_init(&req->msg);
 281
 282         /* activate reference, so it has time to settle; */
 283         req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 284                          AD7877_POL(ts->stopacq_polarity) |
 285                          AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
 286                          AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
 287
 288         req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
 289
 290         req->command = (u16) command;
 291
 292         req->xfer[0].tx_buf = &req->reset;
 293         req->xfer[0].len = 2;
 294         req->xfer[0].cs_change = 1;
 295
 296         req->xfer[1].tx_buf = &req->ref_on;
 297         req->xfer[1].len = 2;
 298         req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 299         req->xfer[1].cs_change = 1;
 300
 301         req->xfer[2].tx_buf = &req->command;
 302         req->xfer[2].len = 2;
 303         req->xfer[2].delay_usecs = ts->vref_delay_usecs;
 304         req->xfer[2].cs_change = 1;
 305
 306         req->xfer[3].rx_buf = &req->sample;
 307         req->xfer[3].len = 2;
 308         req->xfer[3].cs_change = 1;
 309
 310         req->xfer[4].tx_buf = &ts->cmd_crtl2;   /*REF OFF*/
 311         req->xfer[4].len = 2;
 312         req->xfer[4].cs_change = 1;
 313
 314         req->xfer[5].tx_buf = &ts->cmd_crtl1;   /*DEFAULT*/
 315         req->xfer[5].len = 2;
 316
 317         /* group all the transfers together, so we can't interfere with
 318          * reading touchscreen state; disable penirq while sampling
 319          */
 320         for (i = 0; i < 6; i++)
 321                 spi_message_add_tail(&req->xfer[i], &req->msg);
 322
 323         status = spi_sync(spi, &req->msg);
 324         sample = req->sample;
 325
 326         kfree(req);
 327
 328         return status ? : sample;
 329 }
 330
 331 static int ad7877_process_data(struct ad7877 *ts)
 332 {
 333         struct input_dev *input_dev = ts->input;
 334         unsigned Rt;
 335         u16 x, y, z1, z2;
 336
 337         x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
 338         y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
 339         z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
 340         z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
 341
 342         /*
 343          * The samples processed here are already preprocessed by the AD7877.
 344          * The preprocessing function consists of an averaging filter.
 345          * The combination of 'first conversion delay' and averaging provides a robust solution,
 346          * discarding the spurious noise in the signal and keeping only the data of interest.
 347          * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
 348          * Other user-programmable conversion controls include variable acquisition time,
 349          * and first conversion delay. Up to 16 averages can be taken per conversion.
 350          */
 351
 352         if (likely(x && z1)) {
 353                 /* compute touch pressure resistance using equation #1 */
 354                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 355                 Rt /= z1;
 356                 Rt = (Rt + 2047) >> 12;
 357
 358                 /*
 359                  * Sample found inconsistent, pressure is beyond
 360                  * the maximum. Don't report it to user space.
 361                  */
 362                 if (Rt > ts->pressure_max)
 363                         return -EINVAL;
 364
 365                 if (!timer_pending(&ts->timer))
 366                         input_report_key(input_dev, BTN_TOUCH, 1);
 367
 368                 input_report_abs(input_dev, ABS_X, x);
 369                 input_report_abs(input_dev, ABS_Y, y);
 370                 input_report_abs(input_dev, ABS_PRESSURE, Rt);
 371                 input_sync(input_dev);
 372
 373                 return 0;
 374         }
 375
 376         return -EINVAL;
 377 }
 378
 379 static inline void ad7877_ts_event_release(struct ad7877 *ts)
 380 {
 381         struct input_dev *input_dev = ts->input;
 382
 383         input_report_abs(input_dev, ABS_PRESSURE, 0);
 384         input_report_key(input_dev, BTN_TOUCH, 0);
 385         input_sync(input_dev);
 386 }
 387
 388 static void ad7877_timer(struct timer_list *t)
 389 {
 390         struct ad7877 *ts = from_timer(ts, t, timer);
 391         unsigned long flags;
 392
 393         spin_lock_irqsave(&ts->lock, flags);
 394         ad7877_ts_event_release(ts);
 395         spin_unlock_irqrestore(&ts->lock, flags);
 396 }
 397
 398 static irqreturn_t ad7877_irq(int irq, void *handle)
 399 {
 400         struct ad7877 *ts = handle;
 401         unsigned long flags;
 402         int error;
 403
 404         error = spi_sync(ts->spi, &ts->msg);
 405         if (error) {
 406                 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 407                 goto out;
 408         }
 409
 410         spin_lock_irqsave(&ts->lock, flags);
 411         error = ad7877_process_data(ts);
 412         if (!error)
 413                 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 414         spin_unlock_irqrestore(&ts->lock, flags);
 415
 416 out:
 417         return IRQ_HANDLED;
 418 }
 419
 420 static void ad7877_disable(void *data)
 421 {
 422         struct ad7877 *ts = data;
 423
 424         mutex_lock(&ts->mutex);
 425
 426         if (!ts->disabled) {
 427                 ts->disabled = true;
 428                 disable_irq(ts->spi->irq);
 429
 430                 if (del_timer_sync(&ts->timer))
 431                         ad7877_ts_event_release(ts);
 432         }
 433
 434         /*
 435          * We know the chip's in lowpower mode since we always
 436          * leave it that way after every request
 437          */
 438
 439         mutex_unlock(&ts->mutex);
 440 }
 441
 442 static void ad7877_enable(struct ad7877 *ts)
 443 {
 444         mutex_lock(&ts->mutex);
 445
 446         if (ts->disabled) {
 447                 ts->disabled = false;
 448                 enable_irq(ts->spi->irq);
 449         }
 450
 451         mutex_unlock(&ts->mutex);
 452 }
 453
 454 #define SHOW(name) static ssize_t \
 455 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 456 { \
 457         struct ad7877 *ts = dev_get_drvdata(dev); \
 458         ssize_t v = ad7877_read_adc(ts->spi, \
 459                         AD7877_READ_CHAN(name)); \
 460         if (v < 0) \
 461                 return v; \
 462         return sprintf(buf, "%u\n", (unsigned) v); \
 463 } \
 464 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 465
 466 SHOW(aux1)
 467 SHOW(aux2)
 468 SHOW(aux3)
 469 SHOW(bat1)
 470 SHOW(bat2)
 471 SHOW(temp1)
 472 SHOW(temp2)
 473
 474 static ssize_t ad7877_disable_show(struct device *dev,
 475                                      struct device_attribute *attr, char *buf)
 476 {
 477         struct ad7877 *ts = dev_get_drvdata(dev);
 478
 479         return sprintf(buf, "%u\n", ts->disabled);
 480 }
 481
 482 static ssize_t ad7877_disable_store(struct device *dev,
 483                                      struct device_attribute *attr,
 484                                      const char *buf, size_t count)
 485 {
 486         struct ad7877 *ts = dev_get_drvdata(dev);
 487         unsigned int val;
 488         int error;
 489
 490         error = kstrtouint(buf, 10, &val);
 491         if (error)
 492                 return error;
 493
 494         if (val)
 495                 ad7877_disable(ts);
 496         else
 497                 ad7877_enable(ts);
 498
 499         return count;
 500 }
 501
 502 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
 503
 504 static ssize_t ad7877_dac_show(struct device *dev,
 505                                      struct device_attribute *attr, char *buf)
 506 {
 507         struct ad7877 *ts = dev_get_drvdata(dev);
 508
 509         return sprintf(buf, "%u\n", ts->dac);
 510 }
 511
 512 static ssize_t ad7877_dac_store(struct device *dev,
 513                                      struct device_attribute *attr,
 514                                      const char *buf, size_t count)
 515 {
 516         struct ad7877 *ts = dev_get_drvdata(dev);
 517         unsigned int val;
 518         int error;
 519
 520         error = kstrtouint(buf, 10, &val);
 521         if (error)
 522                 return error;
 523
 524         mutex_lock(&ts->mutex);
 525         ts->dac = val & 0xFF;
 526         ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
 527         mutex_unlock(&ts->mutex);
 528
 529         return count;
 530 }
 531
 532 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
 533
 534 static ssize_t ad7877_gpio3_show(struct device *dev,
 535                                      struct device_attribute *attr, char *buf)
 536 {
 537         struct ad7877 *ts = dev_get_drvdata(dev);
 538
 539         return sprintf(buf, "%u\n", ts->gpio3);
 540 }
 541
 542 static ssize_t ad7877_gpio3_store(struct device *dev,
 543                                      struct device_attribute *attr,
 544                                      const char *buf, size_t count)
 545 {
 546         struct ad7877 *ts = dev_get_drvdata(dev);
 547         unsigned int val;
 548         int error;
 549
 550         error = kstrtouint(buf, 10, &val);
 551         if (error)
 552                 return error;
 553
 554         mutex_lock(&ts->mutex);
 555         ts->gpio3 = !!val;
 556         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 557                  (ts->gpio4 << 4) | (ts->gpio3 << 5));
 558         mutex_unlock(&ts->mutex);
 559
 560         return count;
 561 }
 562
 563 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
 564
 565 static ssize_t ad7877_gpio4_show(struct device *dev,
 566                                      struct device_attribute *attr, char *buf)
 567 {
 568         struct ad7877 *ts = dev_get_drvdata(dev);
 569
 570         return sprintf(buf, "%u\n", ts->gpio4);
 571 }
 572
 573 static ssize_t ad7877_gpio4_store(struct device *dev,
 574                                      struct device_attribute *attr,
 575                                      const char *buf, size_t count)
 576 {
 577         struct ad7877 *ts = dev_get_drvdata(dev);
 578         unsigned int val;
 579         int error;
 580
 581         error = kstrtouint(buf, 10, &val);
 582         if (error)
 583                 return error;
 584
 585         mutex_lock(&ts->mutex);
 586         ts->gpio4 = !!val;
 587         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 588                      (ts->gpio4 << 4) | (ts->gpio3 << 5));
 589         mutex_unlock(&ts->mutex);
 590
 591         return count;
 592 }
 593
 594 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
 595
 596 static struct attribute *ad7877_attributes[] = {
 597         &dev_attr_temp1.attr,
 598         &dev_attr_temp2.attr,
 599         &dev_attr_aux1.attr,
 600         &dev_attr_aux2.attr,
 601         &dev_attr_aux3.attr,
 602         &dev_attr_bat1.attr,
 603         &dev_attr_bat2.attr,
 604         &dev_attr_disable.attr,
 605         &dev_attr_dac.attr,
 606         &dev_attr_gpio3.attr,
 607         &dev_attr_gpio4.attr,
 608         NULL
 609 };
 610
 611 static umode_t ad7877_attr_is_visible(struct kobject *kobj,
 612                                      struct attribute *attr, int n)
 613 {
 614         umode_t mode = attr->mode;
 615
 616         if (attr == &dev_attr_aux3.attr) {
 617                 if (gpio3)
 618                         mode = 0;
 619         } else if (attr == &dev_attr_gpio3.attr) {
 620                 if (!gpio3)
 621                         mode = 0;
 622         }
 623
 624         return mode;
 625 }
 626
 627 static const struct attribute_group ad7877_attr_group = {
 628         .is_visible     = ad7877_attr_is_visible,
 629         .attrs          = ad7877_attributes,
 630 };
 631
 632 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
 633 {
 634         struct spi_message *m;
 635         int i;
 636
 637         ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 638                         AD7877_POL(ts->stopacq_polarity) |
 639                         AD7877_AVG(ts->averaging) | AD7877_PM(1) |
 640                         AD7877_TMR(ts->pen_down_acc_interval) |
 641                         AD7877_ACQ(ts->acquisition_time) |
 642                         AD7877_FCD(ts->first_conversion_delay);
 643
 644         ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
 645
 646         ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
 647                         AD7877_READADD(AD7877_REG_XPLUS-1) |
 648                         AD7877_MODE_SEQ1 | AD7877_DFR;
 649
 650         ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
 651
 652         ts->cmd_dummy = 0;
 653
 654         m = &ts->msg;
 655
 656         spi_message_init(m);
 657
 658         m->context = ts;
 659
 660         ts->xfer[0].tx_buf = &ts->cmd_crtl1;
 661         ts->xfer[0].len = 2;
 662         ts->xfer[0].cs_change = 1;
 663
 664         spi_message_add_tail(&ts->xfer[0], m);
 665
 666         ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
 667         ts->xfer[1].len = 2;
 668         ts->xfer[1].cs_change = 1;
 669
 670         spi_message_add_tail(&ts->xfer[1], m);
 671
 672         for (i = 0; i < AD7877_NR_SENSE; i++) {
 673                 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
 674                 ts->xfer[i + 2].len = 2;
 675                 if (i < (AD7877_NR_SENSE - 1))
 676                         ts->xfer[i + 2].cs_change = 1;
 677                 spi_message_add_tail(&ts->xfer[i + 2], m);
 678         }
 679 }
 680
 681 static int ad7877_probe(struct spi_device *spi)
 682 {
 683         struct ad7877                   *ts;
 684         struct input_dev                *input_dev;
 685         struct ad7877_platform_data     *pdata = dev_get_platdata(&spi->dev);
 686         int                             err;
 687         u16                             verify;
 688
 689         if (!spi->irq) {
 690                 dev_dbg(&spi->dev, "no IRQ?\n");
 691                 return -ENODEV;
 692         }
 693
 694         if (!pdata) {
 695                 dev_dbg(&spi->dev, "no platform data?\n");
 696                 return -ENODEV;
 697         }
 698
 699         /* don't exceed max specified SPI CLK frequency */
 700         if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
 701                 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
 702                 return -EINVAL;
 703         }
 704
 705         spi->bits_per_word = 16;
 706         err = spi_setup(spi);
 707         if (err) {
 708                 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
 709                 return err;
 710         }
 711
 712         ts = devm_kzalloc(&spi->dev, sizeof(struct ad7877), GFP_KERNEL);
 713         if (!ts)
 714                 return -ENOMEM;
 715
 716         input_dev = devm_input_allocate_device(&spi->dev);
 717         if (!input_dev)
 718                 return -ENOMEM;
 719
 720         err = devm_add_action_or_reset(&spi->dev, ad7877_disable, ts);
 721         if (err)
 722                 return err;
 723
 724         spi_set_drvdata(spi, ts);
 725         ts->spi = spi;
 726         ts->input = input_dev;
 727
 728         timer_setup(&ts->timer, ad7877_timer, 0);
 729         mutex_init(&ts->mutex);
 730         spin_lock_init(&ts->lock);
 731
 732         ts->model = pdata->model ? : 7877;
 733         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 734         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 735         ts->pressure_max = pdata->pressure_max ? : ~0;
 736
 737         ts->stopacq_polarity = pdata->stopacq_polarity;
 738         ts->first_conversion_delay = pdata->first_conversion_delay;
 739         ts->acquisition_time = pdata->acquisition_time;
 740         ts->averaging = pdata->averaging;
 741         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 742
 743         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 744
 745         input_dev->name = "AD7877 Touchscreen";
 746         input_dev->phys = ts->phys;
 747         input_dev->dev.parent = &spi->dev;
 748
 749         __set_bit(EV_KEY, input_dev->evbit);
 750         __set_bit(BTN_TOUCH, input_dev->keybit);
 751         __set_bit(EV_ABS, input_dev->evbit);
 752         __set_bit(ABS_X, input_dev->absbit);
 753         __set_bit(ABS_Y, input_dev->absbit);
 754         __set_bit(ABS_PRESSURE, input_dev->absbit);
 755
 756         input_set_abs_params(input_dev, ABS_X,
 757                         pdata->x_min ? : 0,
 758                         pdata->x_max ? : MAX_12BIT,
 759                         0, 0);
 760         input_set_abs_params(input_dev, ABS_Y,
 761                         pdata->y_min ? : 0,
 762                         pdata->y_max ? : MAX_12BIT,
 763                         0, 0);
 764         input_set_abs_params(input_dev, ABS_PRESSURE,
 765                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 766
 767         ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
 768
 769         verify = ad7877_read(spi, AD7877_REG_SEQ1);
 770
 771         if (verify != AD7877_MM_SEQUENCE) {
 772                 dev_err(&spi->dev, "%s: Failed to probe %s\n",
 773                         dev_name(&spi->dev), input_dev->name);
 774                 return -ENODEV;
 775         }
 776
 777         if (gpio3)
 778                 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
 779
 780         ad7877_setup_ts_def_msg(spi, ts);
 781
 782         /* Request AD7877 /DAV GPIO interrupt */
 783
 784         err = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, ad7877_irq,
 785                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 786                                         spi->dev.driver->name, ts);
 787         if (err) {
 788                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 789                 return err;
 790         }
 791
 792         err = devm_device_add_group(&spi->dev, &ad7877_attr_group);
 793         if (err)
 794                 return err;
 795
 796         err = input_register_device(input_dev);
 797         if (err)
 798                 return err;
 799
 800         return 0;
 801 }
 802
 803 static int __maybe_unused ad7877_suspend(struct device *dev)
 804 {
 805         struct ad7877 *ts = dev_get_drvdata(dev);
 806
 807         ad7877_disable(ts);
 808
 809         return 0;
 810 }
 811
 812 static int __maybe_unused ad7877_resume(struct device *dev)
 813 {
 814         struct ad7877 *ts = dev_get_drvdata(dev);
 815
 816         ad7877_enable(ts);
 817
 818         return 0;
 819 }
 820
 821 static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
 822
 823 static struct spi_driver ad7877_driver = {
 824         .driver = {
 825                 .name   = "ad7877",
 826                 .pm     = &ad7877_pm,
 827         },
 828         .probe          = ad7877_probe,
 829 };
 830
 831 module_spi_driver(ad7877_driver);
 832
 833 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 834 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
 835 MODULE_LICENSE("GPL");
 836 MODULE_ALIAS("spi:ad7877");