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         unsigned                disabled:1;     /* P: mutex */
 195         unsigned                gpio3:1;        /* P: mutex */
 196         unsigned                gpio4:1;        /* P: mutex */
 197
 198         spinlock_t              lock;
 199         struct timer_list       timer;          /* P: lock */
 200         unsigned                pending:1;      /* 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 int gpio3;
 210 module_param(gpio3, int, 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
 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
 299         req->xfer[1].tx_buf = &req->ref_on;
 300         req->xfer[1].len = 2;
 301         req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 302
 303         req->xfer[2].tx_buf = &req->command;
 304         req->xfer[2].len = 2;
 305         req->xfer[2].delay_usecs = ts->vref_delay_usecs;
 306
 307         req->xfer[3].rx_buf = &req->sample;
 308         req->xfer[3].len = 2;
 309
 310         req->xfer[4].tx_buf = &ts->cmd_crtl2;   /*REF OFF*/
 311         req->xfer[4].len = 2;
 312
 313         req->xfer[5].tx_buf = &ts->cmd_crtl1;   /*DEFAULT*/
 314         req->xfer[5].len = 2;
 315
 316         /* group all the transfers together, so we can't interfere with
 317          * reading touchscreen state; disable penirq while sampling
 318          */
 319         for (i = 0; i < 6; i++)
 320                 spi_message_add_tail(&req->xfer[i], &req->msg);
 321
 322         status = spi_sync(spi, &req->msg);
 323         sample = req->sample;
 324
 325         kfree(req);
 326
 327         return status ? : sample;
 328 }
 329
 330 static void ad7877_rx(struct ad7877 *ts)
 331 {
 332         struct input_dev *input_dev = ts->input;
 333         unsigned Rt;
 334         u16 x, y, z1, z2;
 335
 336         x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
 337         y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
 338         z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
 339         z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
 340
 341         /*
 342          * The samples processed here are already preprocessed by the AD7877.
 343          * The preprocessing function consists of an averaging filter.
 344          * The combination of 'first conversion delay' and averaging provides a robust solution,
 345          * discarding the spurious noise in the signal and keeping only the data of interest.
 346          * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
 347          * Other user-programmable conversion controls include variable acquisition time,
 348          * and first conversion delay. Up to 16 averages can be taken per conversion.
 349          */
 350
 351         if (likely(x && z1)) {
 352                 /* compute touch pressure resistance using equation #1 */
 353                 Rt = (z2 - z1) * x * ts->x_plate_ohms;
 354                 Rt /= z1;
 355                 Rt = (Rt + 2047) >> 12;
 356
 357                 input_report_abs(input_dev, ABS_X, x);
 358                 input_report_abs(input_dev, ABS_Y, y);
 359                 input_report_abs(input_dev, ABS_PRESSURE, Rt);
 360                 input_sync(input_dev);
 361         }
 362 }
 363
 364 static inline void ad7877_ts_event_release(struct ad7877 *ts)
 365 {
 366         struct input_dev *input_dev = ts->input;
 367
 368         input_report_abs(input_dev, ABS_PRESSURE, 0);
 369         input_sync(input_dev);
 370 }
 371
 372 static void ad7877_timer(unsigned long handle)
 373 {
 374         struct ad7877 *ts = (void *)handle;
 375
 376         ad7877_ts_event_release(ts);
 377 }
 378
 379 static irqreturn_t ad7877_irq(int irq, void *handle)
 380 {
 381         struct ad7877 *ts = handle;
 382         unsigned long flags;
 383         int status;
 384
 385         /*
 386          * The repeated conversion sequencer controlled by TMR kicked off
 387          * too fast. We ignore the last and process the sample sequence
 388          * currently in the queue. It can't be older than 9.4ms, and we
 389          * need to avoid that ts->msg doesn't get issued twice while in work.
 390          */
 391
 392         spin_lock_irqsave(&ts->lock, flags);
 393         if (!ts->pending) {
 394                 ts->pending = 1;
 395
 396                 status = spi_async(ts->spi, &ts->msg);
 397                 if (status)
 398                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", status);
 399         }
 400         spin_unlock_irqrestore(&ts->lock, flags);
 401
 402         return IRQ_HANDLED;
 403 }
 404
 405 static void ad7877_callback(void *_ts)
 406 {
 407         struct ad7877 *ts = _ts;
 408
 409         spin_lock_irq(&ts->lock);
 410
 411         ad7877_rx(ts);
 412         ts->pending = 0;
 413         mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 414
 415         spin_unlock_irq(&ts->lock);
 416 }
 417
 418 static void ad7877_disable(struct ad7877 *ts)
 419 {
 420         mutex_lock(&ts->mutex);
 421
 422         if (!ts->disabled) {
 423                 ts->disabled = 1;
 424                 disable_irq(ts->spi->irq);
 425
 426                 /* Wait for spi_async callback */
 427                 while (ts->pending)
 428                         msleep(1);
 429
 430                 if (del_timer_sync(&ts->timer))
 431                         ad7877_ts_event_release(ts);
 432         }
 433
 434         /* we know the chip's in lowpower mode since we always
 435          * leave it that way after every request
 436          */
 437
 438         mutex_unlock(&ts->mutex);
 439 }
 440
 441 static void ad7877_enable(struct ad7877 *ts)
 442 {
 443         mutex_lock(&ts->mutex);
 444
 445         if (ts->disabled) {
 446                 ts->disabled = 0;
 447                 enable_irq(ts->spi->irq);
 448         }
 449
 450         mutex_unlock(&ts->mutex);
 451 }
 452
 453 #define SHOW(name) static ssize_t \
 454 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 455 { \
 456         struct ad7877   *ts = dev_get_drvdata(dev); \
 457         ssize_t v = ad7877_read_adc(ts->spi, \
 458                         AD7877_READ_CHAN(name)); \
 459         if (v < 0) \
 460                 return v; \
 461         return sprintf(buf, "%u\n", (unsigned) v); \
 462 } \
 463 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 464
 465 SHOW(aux1)
 466 SHOW(aux2)
 467 SHOW(aux3)
 468 SHOW(bat1)
 469 SHOW(bat2)
 470 SHOW(temp1)
 471 SHOW(temp2)
 472
 473 static ssize_t ad7877_disable_show(struct device *dev,
 474                                      struct device_attribute *attr, char *buf)
 475 {
 476         struct ad7877   *ts = dev_get_drvdata(dev);
 477
 478         return sprintf(buf, "%u\n", ts->disabled);
 479 }
 480
 481 static ssize_t ad7877_disable_store(struct device *dev,
 482                                      struct device_attribute *attr,
 483                                      const char *buf, size_t count)
 484 {
 485         struct ad7877 *ts = dev_get_drvdata(dev);
 486         unsigned long val;
 487         int error;
 488
 489         error = strict_strtoul(buf, 10, &val);
 490         if (error)
 491                 return error;
 492
 493         if (val)
 494                 ad7877_disable(ts);
 495         else
 496                 ad7877_enable(ts);
 497
 498         return count;
 499 }
 500
 501 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
 502
 503 static ssize_t ad7877_dac_show(struct device *dev,
 504                                      struct device_attribute *attr, char *buf)
 505 {
 506         struct ad7877   *ts = dev_get_drvdata(dev);
 507
 508         return sprintf(buf, "%u\n", ts->dac);
 509 }
 510
 511 static ssize_t ad7877_dac_store(struct device *dev,
 512                                      struct device_attribute *attr,
 513                                      const char *buf, size_t count)
 514 {
 515         struct ad7877 *ts = dev_get_drvdata(dev);
 516         unsigned long val;
 517         int error;
 518
 519         error = strict_strtoul(buf, 10, &val);
 520         if (error)
 521                 return error;
 522
 523         mutex_lock(&ts->mutex);
 524         ts->dac = val & 0xFF;
 525         ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
 526         mutex_unlock(&ts->mutex);
 527
 528         return count;
 529 }
 530
 531 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
 532
 533 static ssize_t ad7877_gpio3_show(struct device *dev,
 534                                      struct device_attribute *attr, char *buf)
 535 {
 536         struct ad7877   *ts = dev_get_drvdata(dev);
 537
 538         return sprintf(buf, "%u\n", ts->gpio3);
 539 }
 540
 541 static ssize_t ad7877_gpio3_store(struct device *dev,
 542                                      struct device_attribute *attr,
 543                                      const char *buf, size_t count)
 544 {
 545         struct ad7877 *ts = dev_get_drvdata(dev);
 546         unsigned long val;
 547         int error;
 548
 549         error = strict_strtoul(buf, 10, &val);
 550         if (error)
 551                 return error;
 552
 553         mutex_lock(&ts->mutex);
 554         ts->gpio3 = !!val;
 555         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 556                  (ts->gpio4 << 4) | (ts->gpio3 << 5));
 557         mutex_unlock(&ts->mutex);
 558
 559         return count;
 560 }
 561
 562 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
 563
 564 static ssize_t ad7877_gpio4_show(struct device *dev,
 565                                      struct device_attribute *attr, char *buf)
 566 {
 567         struct ad7877   *ts = dev_get_drvdata(dev);
 568
 569         return sprintf(buf, "%u\n", ts->gpio4);
 570 }
 571
 572 static ssize_t ad7877_gpio4_store(struct device *dev,
 573                                      struct device_attribute *attr,
 574                                      const char *buf, size_t count)
 575 {
 576         struct ad7877 *ts = dev_get_drvdata(dev);
 577         unsigned long val;
 578         int error;
 579
 580         error = strict_strtoul(buf, 10, &val);
 581         if (error)
 582                 return error;
 583
 584         mutex_lock(&ts->mutex);
 585         ts->gpio4 = !!val;
 586         ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
 587                      (ts->gpio4 << 4) | (ts->gpio3 << 5));
 588         mutex_unlock(&ts->mutex);
 589
 590         return count;
 591 }
 592
 593 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
 594
 595 static struct attribute *ad7877_attributes[] = {
 596         &dev_attr_temp1.attr,
 597         &dev_attr_temp2.attr,
 598         &dev_attr_aux1.attr,
 599         &dev_attr_aux2.attr,
 600         &dev_attr_bat1.attr,
 601         &dev_attr_bat2.attr,
 602         &dev_attr_disable.attr,
 603         &dev_attr_dac.attr,
 604         &dev_attr_gpio4.attr,
 605         NULL
 606 };
 607
 608 static const struct attribute_group ad7877_attr_group = {
 609         .attrs = ad7877_attributes,
 610 };
 611
 612 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
 613 {
 614         struct spi_message *m;
 615         int i;
 616
 617         ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
 618                         AD7877_POL(ts->stopacq_polarity) |
 619                         AD7877_AVG(ts->averaging) | AD7877_PM(1) |
 620                         AD7877_TMR(ts->pen_down_acc_interval) |
 621                         AD7877_ACQ(ts->acquisition_time) |
 622                         AD7877_FCD(ts->first_conversion_delay);
 623
 624         ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
 625
 626         ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
 627                         AD7877_READADD(AD7877_REG_XPLUS-1) |
 628                         AD7877_MODE_SEQ1 | AD7877_DFR;
 629
 630         ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
 631
 632         ts->cmd_dummy = 0;
 633
 634         m = &ts->msg;
 635
 636         spi_message_init(m);
 637
 638         m->complete = ad7877_callback;
 639         m->context = ts;
 640
 641         ts->xfer[0].tx_buf = &ts->cmd_crtl1;
 642         ts->xfer[0].len = 2;
 643
 644         spi_message_add_tail(&ts->xfer[0], m);
 645
 646         ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
 647         ts->xfer[1].len = 2;
 648
 649         spi_message_add_tail(&ts->xfer[1], m);
 650
 651         for (i = 0; i < 11; i++) {
 652                 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
 653                 ts->xfer[i + 2].len = 2;
 654                 spi_message_add_tail(&ts->xfer[i + 2], m);
 655         }
 656 }
 657
 658 static int __devinit ad7877_probe(struct spi_device *spi)
 659 {
 660         struct ad7877                   *ts;
 661         struct input_dev                *input_dev;
 662         struct ad7877_platform_data     *pdata = spi->dev.platform_data;
 663         int                             err;
 664         u16                             verify;
 665
 666         if (!spi->irq) {
 667                 dev_dbg(&spi->dev, "no IRQ?\n");
 668                 return -ENODEV;
 669         }
 670
 671         if (!pdata) {
 672                 dev_dbg(&spi->dev, "no platform data?\n");
 673                 return -ENODEV;
 674         }
 675
 676         /* don't exceed max specified SPI CLK frequency */
 677         if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
 678                 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
 679                 return -EINVAL;
 680         }
 681
 682         spi->bits_per_word = 16;
 683         err = spi_setup(spi);
 684         if (err) {
 685                 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
 686                 return err;
 687         }
 688
 689         ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
 690         input_dev = input_allocate_device();
 691         if (!ts || !input_dev) {
 692                 err = -ENOMEM;
 693                 goto err_free_mem;
 694         }
 695
 696         dev_set_drvdata(&spi->dev, ts);
 697         ts->spi = spi;
 698         ts->input = input_dev;
 699
 700         setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
 701         mutex_init(&ts->mutex);
 702         spin_lock_init(&ts->lock);
 703
 704         ts->model = pdata->model ? : 7877;
 705         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 706         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 707         ts->pressure_max = pdata->pressure_max ? : ~0;
 708
 709         ts->stopacq_polarity = pdata->stopacq_polarity;
 710         ts->first_conversion_delay = pdata->first_conversion_delay;
 711         ts->acquisition_time = pdata->acquisition_time;
 712         ts->averaging = pdata->averaging;
 713         ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 714
 715         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 716
 717         input_dev->name = "AD7877 Touchscreen";
 718         input_dev->phys = ts->phys;
 719         input_dev->dev.parent = &spi->dev;
 720
 721         __set_bit(EV_ABS, input_dev->evbit);
 722         __set_bit(ABS_X, input_dev->absbit);
 723         __set_bit(ABS_Y, input_dev->absbit);
 724         __set_bit(ABS_PRESSURE, input_dev->absbit);
 725
 726         input_set_abs_params(input_dev, ABS_X,
 727                         pdata->x_min ? : 0,
 728                         pdata->x_max ? : MAX_12BIT,
 729                         0, 0);
 730         input_set_abs_params(input_dev, ABS_Y,
 731                         pdata->y_min ? : 0,
 732                         pdata->y_max ? : MAX_12BIT,
 733                         0, 0);
 734         input_set_abs_params(input_dev, ABS_PRESSURE,
 735                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 736
 737         ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
 738
 739         verify = ad7877_read(spi, AD7877_REG_SEQ1);
 740
 741         if (verify != AD7877_MM_SEQUENCE){
 742                 dev_err(&spi->dev, "%s: Failed to probe %s\n",
 743                         dev_name(&spi->dev), input_dev->name);
 744                 err = -ENODEV;
 745                 goto err_free_mem;
 746         }
 747
 748         if (gpio3)
 749                 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
 750
 751         ad7877_setup_ts_def_msg(spi, ts);
 752
 753         /* Request AD7877 /DAV GPIO interrupt */
 754
 755         err = request_irq(spi->irq, ad7877_irq, IRQF_TRIGGER_FALLING,
 756                         spi->dev.driver->name, ts);
 757         if (err) {
 758                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 759                 goto err_free_mem;
 760         }
 761
 762         err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
 763         if (err)
 764                 goto err_free_irq;
 765
 766         err = device_create_file(&spi->dev,
 767                                  gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 768         if (err)
 769                 goto err_remove_attr_group;
 770
 771         err = input_register_device(input_dev);
 772         if (err)
 773                 goto err_remove_attr;
 774
 775         return 0;
 776
 777 err_remove_attr:
 778         device_remove_file(&spi->dev,
 779                            gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 780 err_remove_attr_group:
 781         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 782 err_free_irq:
 783         free_irq(spi->irq, ts);
 784 err_free_mem:
 785         input_free_device(input_dev);
 786         kfree(ts);
 787         dev_set_drvdata(&spi->dev, NULL);
 788         return err;
 789 }
 790
 791 static int __devexit ad7877_remove(struct spi_device *spi)
 792 {
 793         struct ad7877           *ts = dev_get_drvdata(&spi->dev);
 794
 795         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 796         device_remove_file(&spi->dev,
 797                            gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 798
 799         ad7877_disable(ts);
 800         free_irq(ts->spi->irq, ts);
 801
 802         input_unregister_device(ts->input);
 803         kfree(ts);
 804
 805         dev_dbg(&spi->dev, "unregistered touchscreen\n");
 806         dev_set_drvdata(&spi->dev, NULL);
 807
 808         return 0;
 809 }
 810
 811 #ifdef CONFIG_PM
 812 static int ad7877_suspend(struct spi_device *spi, pm_message_t message)
 813 {
 814         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 815
 816         ad7877_disable(ts);
 817
 818         return 0;
 819 }
 820
 821 static int ad7877_resume(struct spi_device *spi)
 822 {
 823         struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 824
 825         ad7877_enable(ts);
 826
 827         return 0;
 828 }
 829 #else
 830 #define ad7877_suspend NULL
 831 #define ad7877_resume  NULL
 832 #endif
 833
 834 static struct spi_driver ad7877_driver = {
 835         .driver = {
 836                 .name   = "ad7877",
 837                 .bus    = &spi_bus_type,
 838                 .owner  = THIS_MODULE,
 839         },
 840         .probe          = ad7877_probe,
 841         .remove         = __devexit_p(ad7877_remove),
 842         .suspend        = ad7877_suspend,
 843         .resume         = ad7877_resume,
 844 };
 845
 846 static int __init ad7877_init(void)
 847 {
 848         return spi_register_driver(&ad7877_driver);
 849 }
 850 module_init(ad7877_init);
 851
 852 static void __exit ad7877_exit(void)
 853 {
 854         spi_unregister_driver(&ad7877_driver);
 855 }
 856 module_exit(ad7877_exit);
 857
 858 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 859 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
 860 MODULE_LICENSE("GPL");
 861 MODULE_ALIAS("spi:ad7877");