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(100)
  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         struct spi_message      msg;
 160         struct spi_transfer     xfer[6];
 161
 162         /*
 163          * DMA (thus cache coherency maintenance) requires the
 164          * transfer buffers to live in their own cache lines.
 165          */
 166         u16 sample ____cacheline_aligned;
 167 };
 168
 169 struct ad7877 {
 170         struct input_dev        *input;
 171         char                    phys[32];
 172
 173         struct spi_device       *spi;
 174         u16                     model;
 175         u16                     vref_delay_usecs;
 176         u16                     x_plate_ohms;
 177         u16                     pressure_max;
 178
 179         u16                     cmd_crtl1;
 180         u16                     cmd_crtl2;
 181         u16                     cmd_dummy;
 182         u16                     dac;
 183
 184         u8                      stopacq_polarity;
 185         u8                      first_conversion_delay;
 186         u8                      acquisition_time;
 187         u8                      averaging;
 188         u8                      pen_down_acc_interval;
 189
 190         struct spi_transfer     xfer[AD7877_NR_SENSE + 2];
 191         struct spi_message      msg;
 192
 193         struct mutex            mutex;
 194         bool                    disabled;       /* P: mutex */
 195         bool                    gpio3;          /* P: mutex */
 196         bool                    gpio4;          /* P: mutex */
 197
 198         spinlock_t              lock;
 199         struct timer_list       timer;          /* P: lock */
 200
 201         /*
 202          * DMA (thus cache coherency maintenance) requires the
 203          * transfer buffers to live in their own cache lines.
 204          */
 205         u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
 206 };
 207
 208 static bool gpio3;
 209 module_param(gpio3, bool, 0);
 210 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
 211
 212 /*
 213  * ad7877_read/write are only used for initial setup and for sysfs controls.
 214  * The main traffic is done using spi_async() in the interrupt handler.
 215  */
 216
 217 static int ad7877_read(struct spi_device *spi, u16 reg)
 218 {
 219         struct ser_req *req;
 220         int status, ret;
 221
 222         req = kzalloc(sizeof *req, GFP_KERNEL);
 223         if (!req)
 224                 return -ENOMEM;
 225
 226         spi_message_init(&req->msg);
 227
 228         req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
 229                         AD7877_READADD(reg));
 230         req->xfer[0].tx_buf = &req->command;
 231         req->xfer[0].len = 2;
 232         req->xfer[0].cs_change = 1;
 233
 234         req->xfer[1].rx_buf = &req->sample;
 235         req->xfer[1].len = 2;
 236
 237         spi_message_add_tail(&req->xfer[0], &req->msg);
 238         spi_message_add_tail(&req->xfer[1], &req->msg);
 239
 240         status = spi_sync(spi, &req->msg);
 241         ret = status ? : req->sample;
 242
 243         kfree(req);
 244
 245         return ret;
 246 }
 247
 248 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
 249 {
 250         struct ser_req *req;
 251         int status;
 252
 253         req = kzalloc(sizeof *req, GFP_KERNEL);
 254         if (!req)
 255                 return -ENOMEM;
 256
 257         spi_message_init(&req->msg);
 258
 259         req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
 260         req->xfer[0].tx_buf = &req->command;
 261         req->xfer[0].len = 2;
 262
 263         spi_message_add_tail(&req->xfer[0], &req->msg);
 264
 265         status = spi_sync(spi, &req->msg);
 266
 267         kfree(req);
 268
 269         return status;
 270 }
 271
 272 static int ad7877_read_adc(struct spi_device *spi, unsigned command)
 273 {
 274         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 275         struct ser_req *req;
 276         int status;
 277         int sample;
 278         int i;
 279
 280         req = kzalloc(sizeof *req, GFP_KERNEL);
 281         if (!req)
 282                 return -ENOMEM;
 283
 284         spi_message_init(&req->msg);
 285
 286         /* activate reference, so it has time to settle; */
 287         req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 288                          AD7877_POL(ts->stopacq_polarity) |
 289                          AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
 290                          AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
 291
 292         req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
 293
 294         req->command = (u16) command;
 295
 296         req->xfer[0].tx_buf = &req->reset;
 297         req->xfer[0].len = 2;
 298         req->xfer[0].cs_change = 1;
 299
 300         req->xfer[1].tx_buf = &req->ref_on;
 301         req->xfer[1].len = 2;
 302         req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 303         req->xfer[1].cs_change = 1;
 304
 305         req->xfer[2].tx_buf = &req->command;
 306         req->xfer[2].len = 2;
 307         req->xfer[2].delay_usecs = ts->vref_delay_usecs;
 308         req->xfer[2].cs_change = 1;
 309
 310         req->xfer[3].rx_buf = &req->sample;
 311         req->xfer[3].len = 2;
 312         req->xfer[3].cs_change = 1;
 313
 314         req->xfer[4].tx_buf = &ts->cmd_crtl2;   /*REF OFF*/
 315         req->xfer[4].len = 2;
 316         req->xfer[4].cs_change = 1;
 317
 318         req->xfer[5].tx_buf = &ts->cmd_crtl1;   /*DEFAULT*/
 319         req->xfer[5].len = 2;
 320
 321         /* group all the transfers together, so we can't interfere with
 322          * reading touchscreen state; disable penirq while sampling
 323          */
 324         for (i = 0; i < 6; i++)
 325                 spi_message_add_tail(&req->xfer[i], &req->msg);
 326
 327         status = spi_sync(spi, &req->msg);
 328         sample = req->sample;
 329
 330         kfree(req);
 331
 332         return status ? : sample;
 333 }
 334
 335 static int ad7877_process_data(struct ad7877 *ts)
 336 {
 337         struct input_dev *input_dev = ts->input;
 338         unsigned Rt;
 339         u16 x, y, z1, z2;
 340
 341         x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
 342         y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
 343         z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
 344         z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
 345
 346         /*
 347          * The samples processed here are already preprocessed by the AD7877.
 348          * The preprocessing function consists of an averaging filter.
 349          * The combination of 'first conversion delay' and averaging provides a robust solution,
 350          * discarding the spurious noise in the signal and keeping only the data of interest.
 351          * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
 352          * Other user-programmable conversion controls include variable acquisition time,
 353          * and first conversion delay. Up to 16 averages can be taken per conversion.
 354          */
 355
 356         if (likely(x && z1)) {
 357                 /* compute touch pressure resistance using equation #1 */
 358                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 359                 Rt /= z1;
 360                 Rt = (Rt + 2047) >> 12;
 361
 362                 /*
 363                  * Sample found inconsistent, pressure is beyond
 364                  * the maximum. Don't report it to user space.
 365                  */
 366                 if (Rt > ts->pressure_max)
 367                         return -EINVAL;
 368
 369                 if (!timer_pending(&ts->timer))
 370                         input_report_key(input_dev, BTN_TOUCH, 1);
 371
 372                 input_report_abs(input_dev, ABS_X, x);
 373                 input_report_abs(input_dev, ABS_Y, y);
 374                 input_report_abs(input_dev, ABS_PRESSURE, Rt);
 375                 input_sync(input_dev);
 376
 377                 return 0;
 378         }
 379
 380         return -EINVAL;
 381 }
 382
 383 static inline void ad7877_ts_event_release(struct ad7877 *ts)
 384 {
 385         struct input_dev *input_dev = ts->input;
 386
 387         input_report_abs(input_dev, ABS_PRESSURE, 0);
 388         input_report_key(input_dev, BTN_TOUCH, 0);
 389         input_sync(input_dev);
 390 }
 391
 392 static void ad7877_timer(unsigned long handle)
 393 {
 394         struct ad7877 *ts = (void *)handle;
 395         unsigned long flags;
 396
 397         spin_lock_irqsave(&ts->lock, flags);
 398         ad7877_ts_event_release(ts);
 399         spin_unlock_irqrestore(&ts->lock, flags);
 400 }
 401
 402 static irqreturn_t ad7877_irq(int irq, void *handle)
 403 {
 404         struct ad7877 *ts = handle;
 405         unsigned long flags;
 406         int error;
 407
 408         error = spi_sync(ts->spi, &ts->msg);
 409         if (error) {
 410                 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 411                 goto out;
 412         }
 413
 414         spin_lock_irqsave(&ts->lock, flags);
 415         error = ad7877_process_data(ts);
 416         if (!error)
 417                 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 418         spin_unlock_irqrestore(&ts->lock, flags);
 419
 420 out:
 421         return IRQ_HANDLED;
 422 }
 423
 424 static void ad7877_disable(struct ad7877 *ts)
 425 {
 426         mutex_lock(&ts->mutex);
 427
 428         if (!ts->disabled) {
 429                 ts->disabled = true;
 430                 disable_irq(ts->spi->irq);
 431
 432                 if (del_timer_sync(&ts->timer))
 433                         ad7877_ts_event_release(ts);
 434         }
 435
 436         /*
 437          * We know the chip's in lowpower mode since we always
 438          * leave it that way after every request
 439          */
 440
 441         mutex_unlock(&ts->mutex);
 442 }
 443
 444 static void ad7877_enable(struct ad7877 *ts)
 445 {
 446         mutex_lock(&ts->mutex);
 447
 448         if (ts->disabled) {
 449                 ts->disabled = false;
 450                 enable_irq(ts->spi->irq);
 451         }
 452
 453         mutex_unlock(&ts->mutex);
 454 }
 455
 456 #define SHOW(name) static ssize_t \
 457 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 458 { \
 459         struct ad7877 *ts = dev_get_drvdata(dev); \
 460         ssize_t v = ad7877_read_adc(ts->spi, \
 461                         AD7877_READ_CHAN(name)); \
 462         if (v < 0) \
 463                 return v; \
 464         return sprintf(buf, "%u\n", (unsigned) v); \
 465 } \
 466 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 467
 468 SHOW(aux1)
 469 SHOW(aux2)
 470 SHOW(aux3)
 471 SHOW(bat1)
 472 SHOW(bat2)
 473 SHOW(temp1)
 474 SHOW(temp2)
 475
 476 static ssize_t ad7877_disable_show(struct device *dev,
 477                                      struct device_attribute *attr, char *buf)
 478 {
 479         struct ad7877 *ts = dev_get_drvdata(dev);
 480
 481         return sprintf(buf, "%u\n", ts->disabled);
 482 }
 483
 484 static ssize_t ad7877_disable_store(struct device *dev,
 485                                      struct device_attribute *attr,
 486                                      const char *buf, size_t count)
 487 {
 488         struct ad7877 *ts = dev_get_drvdata(dev);
 489         unsigned long val;
 490         int error;
 491
 492         error = strict_strtoul(buf, 10, &val);
 493         if (error)
 494                 return error;
 495
 496         if (val)
 497                 ad7877_disable(ts);
 498         else
 499                 ad7877_enable(ts);
 500
 501         return count;
 502 }
 503
 504 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
 505
 506 static ssize_t ad7877_dac_show(struct device *dev,
 507                                      struct device_attribute *attr, char *buf)
 508 {
 509         struct ad7877 *ts = dev_get_drvdata(dev);
 510
 511         return sprintf(buf, "%u\n", ts->dac);
 512 }
 513
 514 static ssize_t ad7877_dac_store(struct device *dev,
 515                                      struct device_attribute *attr,
 516                                      const char *buf, size_t count)
 517 {
 518         struct ad7877 *ts = dev_get_drvdata(dev);
 519         unsigned long val;
 520         int error;
 521
 522         error = strict_strtoul(buf, 10, &val);
 523         if (error)
 524                 return error;
 525
 526         mutex_lock(&ts->mutex);
 527         ts->dac = val & 0xFF;
 528         ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
 529         mutex_unlock(&ts->mutex);
 530
 531         return count;
 532 }
 533
 534 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
 535
 536 static ssize_t ad7877_gpio3_show(struct device *dev,
 537                                      struct device_attribute *attr, char *buf)
 538 {
 539         struct ad7877 *ts = dev_get_drvdata(dev);
 540
 541         return sprintf(buf, "%u\n", ts->gpio3);
 542 }
 543
 544 static ssize_t ad7877_gpio3_store(struct device *dev,
 545                                      struct device_attribute *attr,
 546                                      const char *buf, size_t count)
 547 {
 548         struct ad7877 *ts = dev_get_drvdata(dev);
 549         unsigned long val;
 550         int error;
 551
 552         error = strict_strtoul(buf, 10, &val);
 553         if (error)
 554                 return error;
 555
 556         mutex_lock(&ts->mutex);
 557         ts->gpio3 = !!val;
 558         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 559                  (ts->gpio4 << 4) | (ts->gpio3 << 5));
 560         mutex_unlock(&ts->mutex);
 561
 562         return count;
 563 }
 564
 565 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
 566
 567 static ssize_t ad7877_gpio4_show(struct device *dev,
 568                                      struct device_attribute *attr, char *buf)
 569 {
 570         struct ad7877 *ts = dev_get_drvdata(dev);
 571
 572         return sprintf(buf, "%u\n", ts->gpio4);
 573 }
 574
 575 static ssize_t ad7877_gpio4_store(struct device *dev,
 576                                      struct device_attribute *attr,
 577                                      const char *buf, size_t count)
 578 {
 579         struct ad7877 *ts = dev_get_drvdata(dev);
 580         unsigned long val;
 581         int error;
 582
 583         error = strict_strtoul(buf, 10, &val);
 584         if (error)
 585                 return error;
 586
 587         mutex_lock(&ts->mutex);
 588         ts->gpio4 = !!val;
 589         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 590                      (ts->gpio4 << 4) | (ts->gpio3 << 5));
 591         mutex_unlock(&ts->mutex);
 592
 593         return count;
 594 }
 595
 596 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
 597
 598 static struct attribute *ad7877_attributes[] = {
 599         &dev_attr_temp1.attr,
 600         &dev_attr_temp2.attr,
 601         &dev_attr_aux1.attr,
 602         &dev_attr_aux2.attr,
 603         &dev_attr_aux3.attr,
 604         &dev_attr_bat1.attr,
 605         &dev_attr_bat2.attr,
 606         &dev_attr_disable.attr,
 607         &dev_attr_dac.attr,
 608         &dev_attr_gpio3.attr,
 609         &dev_attr_gpio4.attr,
 610         NULL
 611 };
 612
 613 static mode_t ad7877_attr_is_visible(struct kobject *kobj,
 614                                      struct attribute *attr, int n)
 615 {
 616         mode_t mode = attr->mode;
 617
 618         if (attr == &dev_attr_aux3.attr) {
 619                 if (gpio3)
 620                         mode = 0;
 621         } else if (attr == &dev_attr_gpio3.attr) {
 622                 if (!gpio3)
 623                         mode = 0;
 624         }
 625
 626         return mode;
 627 }
 628
 629 static const struct attribute_group ad7877_attr_group = {
 630         .is_visible     = ad7877_attr_is_visible,
 631         .attrs          = ad7877_attributes,
 632 };
 633
 634 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
 635 {
 636         struct spi_message *m;
 637         int i;
 638
 639         ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 640                         AD7877_POL(ts->stopacq_polarity) |
 641                         AD7877_AVG(ts->averaging) | AD7877_PM(1) |
 642                         AD7877_TMR(ts->pen_down_acc_interval) |
 643                         AD7877_ACQ(ts->acquisition_time) |
 644                         AD7877_FCD(ts->first_conversion_delay);
 645
 646         ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
 647
 648         ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
 649                         AD7877_READADD(AD7877_REG_XPLUS-1) |
 650                         AD7877_MODE_SEQ1 | AD7877_DFR;
 651
 652         ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
 653
 654         ts->cmd_dummy = 0;
 655
 656         m = &ts->msg;
 657
 658         spi_message_init(m);
 659
 660         m->context = ts;
 661
 662         ts->xfer[0].tx_buf = &ts->cmd_crtl1;
 663         ts->xfer[0].len = 2;
 664         ts->xfer[0].cs_change = 1;
 665
 666         spi_message_add_tail(&ts->xfer[0], m);
 667
 668         ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
 669         ts->xfer[1].len = 2;
 670         ts->xfer[1].cs_change = 1;
 671
 672         spi_message_add_tail(&ts->xfer[1], m);
 673
 674         for (i = 0; i < AD7877_NR_SENSE; i++) {
 675                 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
 676                 ts->xfer[i + 2].len = 2;
 677                 if (i < (AD7877_NR_SENSE - 1))
 678                         ts->xfer[i + 2].cs_change = 1;
 679                 spi_message_add_tail(&ts->xfer[i + 2], m);
 680         }
 681 }
 682
 683 static int __devinit ad7877_probe(struct spi_device *spi)
 684 {
 685         struct ad7877                   *ts;
 686         struct input_dev                *input_dev;
 687         struct ad7877_platform_data     *pdata = spi->dev.platform_data;
 688         int                             err;
 689         u16                             verify;
 690
 691         if (!spi->irq) {
 692                 dev_dbg(&spi->dev, "no IRQ?\n");
 693                 return -ENODEV;
 694         }
 695
 696         if (!pdata) {
 697                 dev_dbg(&spi->dev, "no platform data?\n");
 698                 return -ENODEV;
 699         }
 700
 701         /* don't exceed max specified SPI CLK frequency */
 702         if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
 703                 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
 704                 return -EINVAL;
 705         }
 706
 707         spi->bits_per_word = 16;
 708         err = spi_setup(spi);
 709         if (err) {
 710                 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
 711                 return err;
 712         }
 713
 714         ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
 715         input_dev = input_allocate_device();
 716         if (!ts || !input_dev) {
 717                 err = -ENOMEM;
 718                 goto err_free_mem;
 719         }
 720
 721         dev_set_drvdata(&spi->dev, ts);
 722         ts->spi = spi;
 723         ts->input = input_dev;
 724
 725         setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
 726         mutex_init(&ts->mutex);
 727         spin_lock_init(&ts->lock);
 728
 729         ts->model = pdata->model ? : 7877;
 730         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 731         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 732         ts->pressure_max = pdata->pressure_max ? : ~0;
 733
 734         ts->stopacq_polarity = pdata->stopacq_polarity;
 735         ts->first_conversion_delay = pdata->first_conversion_delay;
 736         ts->acquisition_time = pdata->acquisition_time;
 737         ts->averaging = pdata->averaging;
 738         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 739
 740         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 741
 742         input_dev->name = "AD7877 Touchscreen";
 743         input_dev->phys = ts->phys;
 744         input_dev->dev.parent = &spi->dev;
 745
 746         __set_bit(EV_KEY, input_dev->evbit);
 747         __set_bit(BTN_TOUCH, input_dev->keybit);
 748         __set_bit(EV_ABS, input_dev->evbit);
 749         __set_bit(ABS_X, input_dev->absbit);
 750         __set_bit(ABS_Y, input_dev->absbit);
 751         __set_bit(ABS_PRESSURE, input_dev->absbit);
 752
 753         input_set_abs_params(input_dev, ABS_X,
 754                         pdata->x_min ? : 0,
 755                         pdata->x_max ? : MAX_12BIT,
 756                         0, 0);
 757         input_set_abs_params(input_dev, ABS_Y,
 758                         pdata->y_min ? : 0,
 759                         pdata->y_max ? : MAX_12BIT,
 760                         0, 0);
 761         input_set_abs_params(input_dev, ABS_PRESSURE,
 762                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 763
 764         ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
 765
 766         verify = ad7877_read(spi, AD7877_REG_SEQ1);
 767
 768         if (verify != AD7877_MM_SEQUENCE){
 769                 dev_err(&spi->dev, "%s: Failed to probe %s\n",
 770                         dev_name(&spi->dev), input_dev->name);
 771                 err = -ENODEV;
 772                 goto err_free_mem;
 773         }
 774
 775         if (gpio3)
 776                 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
 777
 778         ad7877_setup_ts_def_msg(spi, ts);
 779
 780         /* Request AD7877 /DAV GPIO interrupt */
 781
 782         err = request_threaded_irq(spi->irq, NULL, ad7877_irq,
 783                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 784                                    spi->dev.driver->name, ts);
 785         if (err) {
 786                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 787                 goto err_free_mem;
 788         }
 789
 790         err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
 791         if (err)
 792                 goto err_free_irq;
 793
 794         err = input_register_device(input_dev);
 795         if (err)
 796                 goto err_remove_attr_group;
 797
 798         return 0;
 799
 800 err_remove_attr_group:
 801         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 802 err_free_irq:
 803         free_irq(spi->irq, ts);
 804 err_free_mem:
 805         input_free_device(input_dev);
 806         kfree(ts);
 807         dev_set_drvdata(&spi->dev, NULL);
 808         return err;
 809 }
 810
 811 static int __devexit ad7877_remove(struct spi_device *spi)
 812 {
 813         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 814
 815         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 816
 817         ad7877_disable(ts);
 818         free_irq(ts->spi->irq, ts);
 819
 820         input_unregister_device(ts->input);
 821         kfree(ts);
 822
 823         dev_dbg(&spi->dev, "unregistered touchscreen\n");
 824         dev_set_drvdata(&spi->dev, NULL);
 825
 826         return 0;
 827 }
 828
 829 #ifdef CONFIG_PM
 830 static int ad7877_suspend(struct spi_device *spi, pm_message_t message)
 831 {
 832         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 833
 834         ad7877_disable(ts);
 835
 836         return 0;
 837 }
 838
 839 static int ad7877_resume(struct spi_device *spi)
 840 {
 841         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 842
 843         ad7877_enable(ts);
 844
 845         return 0;
 846 }
 847 #else
 848 #define ad7877_suspend NULL
 849 #define ad7877_resume  NULL
 850 #endif
 851
 852 static struct spi_driver ad7877_driver = {
 853         .driver = {
 854                 .name   = "ad7877",
 855                 .bus    = &spi_bus_type,
 856                 .owner  = THIS_MODULE,
 857         },
 858         .probe          = ad7877_probe,
 859         .remove         = __devexit_p(ad7877_remove),
 860         .suspend        = ad7877_suspend,
 861         .resume         = ad7877_resume,
 862 };
 863
 864 static int __init ad7877_init(void)
 865 {
 866         return spi_register_driver(&ad7877_driver);
 867 }
 868 module_init(ad7877_init);
 869
 870 static void __exit ad7877_exit(void)
 871 {
 872         spi_unregister_driver(&ad7877_driver);
 873 }
 874 module_exit(ad7877_exit);
 875
 876 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 877 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
 878 MODULE_LICENSE("GPL");
 879 MODULE_ALIAS("spi:ad7877");