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/pm.h>
  45 #include <linux/slab.h>
  46 #include <linux/spi/spi.h>
  47 #include <linux/spi/ad7877.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 /*
 214  * ad7877_read/write are only used for initial setup and for sysfs controls.
 215  * The main traffic is done using spi_async() in the interrupt handler.
 216  */
 217
 218 static int ad7877_read(struct spi_device *spi, u16 reg)
 219 {
 220         struct ser_req *req;
 221         int status, ret;
 222
 223         req = kzalloc(sizeof *req, GFP_KERNEL);
 224         if (!req)
 225                 return -ENOMEM;
 226
 227         spi_message_init(&req->msg);
 228
 229         req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
 230                         AD7877_READADD(reg));
 231         req->xfer[0].tx_buf = &req->command;
 232         req->xfer[0].len = 2;
 233         req->xfer[0].cs_change = 1;
 234
 235         req->xfer[1].rx_buf = &req->sample;
 236         req->xfer[1].len = 2;
 237
 238         spi_message_add_tail(&req->xfer[0], &req->msg);
 239         spi_message_add_tail(&req->xfer[1], &req->msg);
 240
 241         status = spi_sync(spi, &req->msg);
 242         ret = status ? : req->sample;
 243
 244         kfree(req);
 245
 246         return ret;
 247 }
 248
 249 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
 250 {
 251         struct ser_req *req;
 252         int status;
 253
 254         req = kzalloc(sizeof *req, GFP_KERNEL);
 255         if (!req)
 256                 return -ENOMEM;
 257
 258         spi_message_init(&req->msg);
 259
 260         req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
 261         req->xfer[0].tx_buf = &req->command;
 262         req->xfer[0].len = 2;
 263
 264         spi_message_add_tail(&req->xfer[0], &req->msg);
 265
 266         status = spi_sync(spi, &req->msg);
 267
 268         kfree(req);
 269
 270         return status;
 271 }
 272
 273 static int ad7877_read_adc(struct spi_device *spi, unsigned command)
 274 {
 275         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 276         struct ser_req *req;
 277         int status;
 278         int sample;
 279         int i;
 280
 281         req = kzalloc(sizeof *req, GFP_KERNEL);
 282         if (!req)
 283                 return -ENOMEM;
 284
 285         spi_message_init(&req->msg);
 286
 287         /* activate reference, so it has time to settle; */
 288         req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 289                          AD7877_POL(ts->stopacq_polarity) |
 290                          AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
 291                          AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
 292
 293         req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
 294
 295         req->command = (u16) command;
 296
 297         req->xfer[0].tx_buf = &req->reset;
 298         req->xfer[0].len = 2;
 299         req->xfer[0].cs_change = 1;
 300
 301         req->xfer[1].tx_buf = &req->ref_on;
 302         req->xfer[1].len = 2;
 303         req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 304         req->xfer[1].cs_change = 1;
 305
 306         req->xfer[2].tx_buf = &req->command;
 307         req->xfer[2].len = 2;
 308         req->xfer[2].delay_usecs = ts->vref_delay_usecs;
 309         req->xfer[2].cs_change = 1;
 310
 311         req->xfer[3].rx_buf = &req->sample;
 312         req->xfer[3].len = 2;
 313         req->xfer[3].cs_change = 1;
 314
 315         req->xfer[4].tx_buf = &ts->cmd_crtl2;   /*REF OFF*/
 316         req->xfer[4].len = 2;
 317         req->xfer[4].cs_change = 1;
 318
 319         req->xfer[5].tx_buf = &ts->cmd_crtl1;   /*DEFAULT*/
 320         req->xfer[5].len = 2;
 321
 322         /* group all the transfers together, so we can't interfere with
 323          * reading touchscreen state; disable penirq while sampling
 324          */
 325         for (i = 0; i < 6; i++)
 326                 spi_message_add_tail(&req->xfer[i], &req->msg);
 327
 328         status = spi_sync(spi, &req->msg);
 329         sample = req->sample;
 330
 331         kfree(req);
 332
 333         return status ? : sample;
 334 }
 335
 336 static int ad7877_process_data(struct ad7877 *ts)
 337 {
 338         struct input_dev *input_dev = ts->input;
 339         unsigned Rt;
 340         u16 x, y, z1, z2;
 341
 342         x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
 343         y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
 344         z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
 345         z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
 346
 347         /*
 348          * The samples processed here are already preprocessed by the AD7877.
 349          * The preprocessing function consists of an averaging filter.
 350          * The combination of 'first conversion delay' and averaging provides a robust solution,
 351          * discarding the spurious noise in the signal and keeping only the data of interest.
 352          * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
 353          * Other user-programmable conversion controls include variable acquisition time,
 354          * and first conversion delay. Up to 16 averages can be taken per conversion.
 355          */
 356
 357         if (likely(x && z1)) {
 358                 /* compute touch pressure resistance using equation #1 */
 359                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 360                 Rt /= z1;
 361                 Rt = (Rt + 2047) >> 12;
 362
 363                 /*
 364                  * Sample found inconsistent, pressure is beyond
 365                  * the maximum. Don't report it to user space.
 366                  */
 367                 if (Rt > ts->pressure_max)
 368                         return -EINVAL;
 369
 370                 if (!timer_pending(&ts->timer))
 371                         input_report_key(input_dev, BTN_TOUCH, 1);
 372
 373                 input_report_abs(input_dev, ABS_X, x);
 374                 input_report_abs(input_dev, ABS_Y, y);
 375                 input_report_abs(input_dev, ABS_PRESSURE, Rt);
 376                 input_sync(input_dev);
 377
 378                 return 0;
 379         }
 380
 381         return -EINVAL;
 382 }
 383
 384 static inline void ad7877_ts_event_release(struct ad7877 *ts)
 385 {
 386         struct input_dev *input_dev = ts->input;
 387
 388         input_report_abs(input_dev, ABS_PRESSURE, 0);
 389         input_report_key(input_dev, BTN_TOUCH, 0);
 390         input_sync(input_dev);
 391 }
 392
 393 static void ad7877_timer(unsigned long handle)
 394 {
 395         struct ad7877 *ts = (void *)handle;
 396         unsigned long flags;
 397
 398         spin_lock_irqsave(&ts->lock, flags);
 399         ad7877_ts_event_release(ts);
 400         spin_unlock_irqrestore(&ts->lock, flags);
 401 }
 402
 403 static irqreturn_t ad7877_irq(int irq, void *handle)
 404 {
 405         struct ad7877 *ts = handle;
 406         unsigned long flags;
 407         int error;
 408
 409         error = spi_sync(ts->spi, &ts->msg);
 410         if (error) {
 411                 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 412                 goto out;
 413         }
 414
 415         spin_lock_irqsave(&ts->lock, flags);
 416         error = ad7877_process_data(ts);
 417         if (!error)
 418                 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 419         spin_unlock_irqrestore(&ts->lock, flags);
 420
 421 out:
 422         return IRQ_HANDLED;
 423 }
 424
 425 static void ad7877_disable(struct ad7877 *ts)
 426 {
 427         mutex_lock(&ts->mutex);
 428
 429         if (!ts->disabled) {
 430                 ts->disabled = true;
 431                 disable_irq(ts->spi->irq);
 432
 433                 if (del_timer_sync(&ts->timer))
 434                         ad7877_ts_event_release(ts);
 435         }
 436
 437         /*
 438          * We know the chip's in lowpower mode since we always
 439          * leave it that way after every request
 440          */
 441
 442         mutex_unlock(&ts->mutex);
 443 }
 444
 445 static void ad7877_enable(struct ad7877 *ts)
 446 {
 447         mutex_lock(&ts->mutex);
 448
 449         if (ts->disabled) {
 450                 ts->disabled = false;
 451                 enable_irq(ts->spi->irq);
 452         }
 453
 454         mutex_unlock(&ts->mutex);
 455 }
 456
 457 #define SHOW(name) static ssize_t \
 458 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 459 { \
 460         struct ad7877 *ts = dev_get_drvdata(dev); \
 461         ssize_t v = ad7877_read_adc(ts->spi, \
 462                         AD7877_READ_CHAN(name)); \
 463         if (v < 0) \
 464                 return v; \
 465         return sprintf(buf, "%u\n", (unsigned) v); \
 466 } \
 467 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 468
 469 SHOW(aux1)
 470 SHOW(aux2)
 471 SHOW(aux3)
 472 SHOW(bat1)
 473 SHOW(bat2)
 474 SHOW(temp1)
 475 SHOW(temp2)
 476
 477 static ssize_t ad7877_disable_show(struct device *dev,
 478                                      struct device_attribute *attr, char *buf)
 479 {
 480         struct ad7877 *ts = dev_get_drvdata(dev);
 481
 482         return sprintf(buf, "%u\n", ts->disabled);
 483 }
 484
 485 static ssize_t ad7877_disable_store(struct device *dev,
 486                                      struct device_attribute *attr,
 487                                      const char *buf, size_t count)
 488 {
 489         struct ad7877 *ts = dev_get_drvdata(dev);
 490         unsigned long val;
 491         int error;
 492
 493         error = strict_strtoul(buf, 10, &val);
 494         if (error)
 495                 return error;
 496
 497         if (val)
 498                 ad7877_disable(ts);
 499         else
 500                 ad7877_enable(ts);
 501
 502         return count;
 503 }
 504
 505 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
 506
 507 static ssize_t ad7877_dac_show(struct device *dev,
 508                                      struct device_attribute *attr, char *buf)
 509 {
 510         struct ad7877 *ts = dev_get_drvdata(dev);
 511
 512         return sprintf(buf, "%u\n", ts->dac);
 513 }
 514
 515 static ssize_t ad7877_dac_store(struct device *dev,
 516                                      struct device_attribute *attr,
 517                                      const char *buf, size_t count)
 518 {
 519         struct ad7877 *ts = dev_get_drvdata(dev);
 520         unsigned long val;
 521         int error;
 522
 523         error = strict_strtoul(buf, 10, &val);
 524         if (error)
 525                 return error;
 526
 527         mutex_lock(&ts->mutex);
 528         ts->dac = val & 0xFF;
 529         ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
 530         mutex_unlock(&ts->mutex);
 531
 532         return count;
 533 }
 534
 535 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
 536
 537 static ssize_t ad7877_gpio3_show(struct device *dev,
 538                                      struct device_attribute *attr, char *buf)
 539 {
 540         struct ad7877 *ts = dev_get_drvdata(dev);
 541
 542         return sprintf(buf, "%u\n", ts->gpio3);
 543 }
 544
 545 static ssize_t ad7877_gpio3_store(struct device *dev,
 546                                      struct device_attribute *attr,
 547                                      const char *buf, size_t count)
 548 {
 549         struct ad7877 *ts = dev_get_drvdata(dev);
 550         unsigned long val;
 551         int error;
 552
 553         error = strict_strtoul(buf, 10, &val);
 554         if (error)
 555                 return error;
 556
 557         mutex_lock(&ts->mutex);
 558         ts->gpio3 = !!val;
 559         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 560                  (ts->gpio4 << 4) | (ts->gpio3 << 5));
 561         mutex_unlock(&ts->mutex);
 562
 563         return count;
 564 }
 565
 566 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
 567
 568 static ssize_t ad7877_gpio4_show(struct device *dev,
 569                                      struct device_attribute *attr, char *buf)
 570 {
 571         struct ad7877 *ts = dev_get_drvdata(dev);
 572
 573         return sprintf(buf, "%u\n", ts->gpio4);
 574 }
 575
 576 static ssize_t ad7877_gpio4_store(struct device *dev,
 577                                      struct device_attribute *attr,
 578                                      const char *buf, size_t count)
 579 {
 580         struct ad7877 *ts = dev_get_drvdata(dev);
 581         unsigned long val;
 582         int error;
 583
 584         error = strict_strtoul(buf, 10, &val);
 585         if (error)
 586                 return error;
 587
 588         mutex_lock(&ts->mutex);
 589         ts->gpio4 = !!val;
 590         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 591                      (ts->gpio4 << 4) | (ts->gpio3 << 5));
 592         mutex_unlock(&ts->mutex);
 593
 594         return count;
 595 }
 596
 597 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
 598
 599 static struct attribute *ad7877_attributes[] = {
 600         &dev_attr_temp1.attr,
 601         &dev_attr_temp2.attr,
 602         &dev_attr_aux1.attr,
 603         &dev_attr_aux2.attr,
 604         &dev_attr_aux3.attr,
 605         &dev_attr_bat1.attr,
 606         &dev_attr_bat2.attr,
 607         &dev_attr_disable.attr,
 608         &dev_attr_dac.attr,
 609         &dev_attr_gpio3.attr,
 610         &dev_attr_gpio4.attr,
 611         NULL
 612 };
 613
 614 static mode_t ad7877_attr_is_visible(struct kobject *kobj,
 615                                      struct attribute *attr, int n)
 616 {
 617         mode_t mode = attr->mode;
 618
 619         if (attr == &dev_attr_aux3.attr) {
 620                 if (gpio3)
 621                         mode = 0;
 622         } else if (attr == &dev_attr_gpio3.attr) {
 623                 if (!gpio3)
 624                         mode = 0;
 625         }
 626
 627         return mode;
 628 }
 629
 630 static const struct attribute_group ad7877_attr_group = {
 631         .is_visible     = ad7877_attr_is_visible,
 632         .attrs          = ad7877_attributes,
 633 };
 634
 635 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
 636 {
 637         struct spi_message *m;
 638         int i;
 639
 640         ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 641                         AD7877_POL(ts->stopacq_polarity) |
 642                         AD7877_AVG(ts->averaging) | AD7877_PM(1) |
 643                         AD7877_TMR(ts->pen_down_acc_interval) |
 644                         AD7877_ACQ(ts->acquisition_time) |
 645                         AD7877_FCD(ts->first_conversion_delay);
 646
 647         ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
 648
 649         ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
 650                         AD7877_READADD(AD7877_REG_XPLUS-1) |
 651                         AD7877_MODE_SEQ1 | AD7877_DFR;
 652
 653         ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
 654
 655         ts->cmd_dummy = 0;
 656
 657         m = &ts->msg;
 658
 659         spi_message_init(m);
 660
 661         m->context = ts;
 662
 663         ts->xfer[0].tx_buf = &ts->cmd_crtl1;
 664         ts->xfer[0].len = 2;
 665         ts->xfer[0].cs_change = 1;
 666
 667         spi_message_add_tail(&ts->xfer[0], m);
 668
 669         ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
 670         ts->xfer[1].len = 2;
 671         ts->xfer[1].cs_change = 1;
 672
 673         spi_message_add_tail(&ts->xfer[1], m);
 674
 675         for (i = 0; i < AD7877_NR_SENSE; i++) {
 676                 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
 677                 ts->xfer[i + 2].len = 2;
 678                 if (i < (AD7877_NR_SENSE - 1))
 679                         ts->xfer[i + 2].cs_change = 1;
 680                 spi_message_add_tail(&ts->xfer[i + 2], m);
 681         }
 682 }
 683
 684 static int __devinit ad7877_probe(struct spi_device *spi)
 685 {
 686         struct ad7877                   *ts;
 687         struct input_dev                *input_dev;
 688         struct ad7877_platform_data     *pdata = spi->dev.platform_data;
 689         int                             err;
 690         u16                             verify;
 691
 692         if (!spi->irq) {
 693                 dev_dbg(&spi->dev, "no IRQ?\n");
 694                 return -ENODEV;
 695         }
 696
 697         if (!pdata) {
 698                 dev_dbg(&spi->dev, "no platform data?\n");
 699                 return -ENODEV;
 700         }
 701
 702         /* don't exceed max specified SPI CLK frequency */
 703         if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
 704                 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
 705                 return -EINVAL;
 706         }
 707
 708         spi->bits_per_word = 16;
 709         err = spi_setup(spi);
 710         if (err) {
 711                 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
 712                 return err;
 713         }
 714
 715         ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
 716         input_dev = input_allocate_device();
 717         if (!ts || !input_dev) {
 718                 err = -ENOMEM;
 719                 goto err_free_mem;
 720         }
 721
 722         dev_set_drvdata(&spi->dev, ts);
 723         ts->spi = spi;
 724         ts->input = input_dev;
 725
 726         setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
 727         mutex_init(&ts->mutex);
 728         spin_lock_init(&ts->lock);
 729
 730         ts->model = pdata->model ? : 7877;
 731         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 732         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 733         ts->pressure_max = pdata->pressure_max ? : ~0;
 734
 735         ts->stopacq_polarity = pdata->stopacq_polarity;
 736         ts->first_conversion_delay = pdata->first_conversion_delay;
 737         ts->acquisition_time = pdata->acquisition_time;
 738         ts->averaging = pdata->averaging;
 739         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 740
 741         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 742
 743         input_dev->name = "AD7877 Touchscreen";
 744         input_dev->phys = ts->phys;
 745         input_dev->dev.parent = &spi->dev;
 746
 747         __set_bit(EV_KEY, input_dev->evbit);
 748         __set_bit(BTN_TOUCH, input_dev->keybit);
 749         __set_bit(EV_ABS, input_dev->evbit);
 750         __set_bit(ABS_X, input_dev->absbit);
 751         __set_bit(ABS_Y, input_dev->absbit);
 752         __set_bit(ABS_PRESSURE, input_dev->absbit);
 753
 754         input_set_abs_params(input_dev, ABS_X,
 755                         pdata->x_min ? : 0,
 756                         pdata->x_max ? : MAX_12BIT,
 757                         0, 0);
 758         input_set_abs_params(input_dev, ABS_Y,
 759                         pdata->y_min ? : 0,
 760                         pdata->y_max ? : MAX_12BIT,
 761                         0, 0);
 762         input_set_abs_params(input_dev, ABS_PRESSURE,
 763                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 764
 765         ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
 766
 767         verify = ad7877_read(spi, AD7877_REG_SEQ1);
 768
 769         if (verify != AD7877_MM_SEQUENCE){
 770                 dev_err(&spi->dev, "%s: Failed to probe %s\n",
 771                         dev_name(&spi->dev), input_dev->name);
 772                 err = -ENODEV;
 773                 goto err_free_mem;
 774         }
 775
 776         if (gpio3)
 777                 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
 778
 779         ad7877_setup_ts_def_msg(spi, ts);
 780
 781         /* Request AD7877 /DAV GPIO interrupt */
 782
 783         err = request_threaded_irq(spi->irq, NULL, ad7877_irq,
 784                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 785                                    spi->dev.driver->name, ts);
 786         if (err) {
 787                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 788                 goto err_free_mem;
 789         }
 790
 791         err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
 792         if (err)
 793                 goto err_free_irq;
 794
 795         err = input_register_device(input_dev);
 796         if (err)
 797                 goto err_remove_attr_group;
 798
 799         return 0;
 800
 801 err_remove_attr_group:
 802         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 803 err_free_irq:
 804         free_irq(spi->irq, ts);
 805 err_free_mem:
 806         input_free_device(input_dev);
 807         kfree(ts);
 808         dev_set_drvdata(&spi->dev, NULL);
 809         return err;
 810 }
 811
 812 static int __devexit ad7877_remove(struct spi_device *spi)
 813 {
 814         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 815
 816         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 817
 818         ad7877_disable(ts);
 819         free_irq(ts->spi->irq, ts);
 820
 821         input_unregister_device(ts->input);
 822         kfree(ts);
 823
 824         dev_dbg(&spi->dev, "unregistered touchscreen\n");
 825         dev_set_drvdata(&spi->dev, NULL);
 826
 827         return 0;
 828 }
 829
 830 #ifdef CONFIG_PM_SLEEP
 831 static int ad7877_suspend(struct device *dev)
 832 {
 833         struct ad7877 *ts = dev_get_drvdata(dev);
 834
 835         ad7877_disable(ts);
 836
 837         return 0;
 838 }
 839
 840 static int ad7877_resume(struct device *dev)
 841 {
 842         struct ad7877 *ts = dev_get_drvdata(dev);
 843
 844         ad7877_enable(ts);
 845
 846         return 0;
 847 }
 848 #endif
 849
 850 static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
 851
 852 static struct spi_driver ad7877_driver = {
 853         .driver = {
 854                 .name   = "ad7877",
 855                 .bus    = &spi_bus_type,
 856                 .owner  = THIS_MODULE,
 857                 .pm     = &ad7877_pm,
 858         },
 859         .probe          = ad7877_probe,
 860         .remove         = __devexit_p(ad7877_remove),
 861 };
 862
 863 static int __init ad7877_init(void)
 864 {
 865         return spi_register_driver(&ad7877_driver);
 866 }
 867 module_init(ad7877_init);
 868
 869 static void __exit ad7877_exit(void)
 870 {
 871         spi_unregister_driver(&ad7877_driver);
 872 }
 873 module_exit(ad7877_exit);
 874
 875 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 876 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
 877 MODULE_LICENSE("GPL");
 878 MODULE_ALIAS("spi:ad7877");