drivers/input/touchscreen/ads7846.c

   1 /*
   2  * ADS7846 based touchscreen and sensor driver
   3  *
   4  * Copyright (c) 2005 David Brownell
   5  * Copyright (c) 2006 Nokia Corporation
   6  * Various changes: Imre Deak <imre.deak@nokia.com>
   7  *
   8  * Using code from:
   9  *  - corgi_ts.c
  10  *      Copyright (C) 2004-2005 Richard Purdie
  11  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  12  *      Copyright (C) 2002 MontaVista Software
  13  *      Copyright (C) 2004 Texas Instruments
  14  *      Copyright (C) 2005 Dirk Behme
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2 as
  18  *  published by the Free Software Foundation.
  19  */
  20 #include <linux/types.h>
  21 #include <linux/hwmon.h>
  22 #include <linux/init.h>
  23 #include <linux/err.h>
  24 #include <linux/sched.h>
  25 #include <linux/delay.h>
  26 #include <linux/input.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/slab.h>
  29 #include <linux/pm.h>
  30 #include <linux/gpio.h>
  31 #include <linux/spi/spi.h>
  32 #include <linux/spi/ads7846.h>
  33 #include <linux/regulator/consumer.h>
  34 #include <asm/irq.h>
  35
  36 /*
  37  * This code has been heavily tested on a Nokia 770, and lightly
  38  * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
  39  * TSC2046 is just newer ads7846 silicon.
  40  * Support for ads7843 tested on Atmel at91sam926x-EK.
  41  * Support for ads7845 has only been stubbed in.
  42  * Support for Analog Devices AD7873 and AD7843 tested.
  43  *
  44  * IRQ handling needs a workaround because of a shortcoming in handling
  45  * edge triggered IRQs on some platforms like the OMAP1/2. These
  46  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
  47  * have to maintain our own SW IRQ disabled status. This should be
  48  * removed as soon as the affected platform's IRQ handling is fixed.
  49  *
  50  * App note sbaa036 talks in more detail about accurate sampling...
  51  * that ought to help in situations like LCDs inducing noise (which
  52  * can also be helped by using synch signals) and more generally.
  53  * This driver tries to utilize the measures described in the app
  54  * note. The strength of filtering can be set in the board-* specific
  55  * files.
  56  */
  57
  58 #define TS_POLL_DELAY   1       /* ms delay before the first sample */
  59 #define TS_POLL_PERIOD  5       /* ms delay between samples */
  60
  61 /* this driver doesn't aim at the peak continuous sample rate */
  62 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
  63
  64 struct ts_event {
  65         /*
  66          * For portability, we can't read 12 bit values using SPI (which
  67          * would make the controller deliver them as native byte order u16
  68          * with msbs zeroed).  Instead, we read them as two 8-bit values,
  69          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
  70          */
  71         u16     x;
  72         u16     y;
  73         u16     z1, z2;
  74         bool    ignore;
  75         u8      x_buf[3];
  76         u8      y_buf[3];
  77 };
  78
  79 /*
  80  * We allocate this separately to avoid cache line sharing issues when
  81  * driver is used with DMA-based SPI controllers (like atmel_spi) on
  82  * systems where main memory is not DMA-coherent (most non-x86 boards).
  83  */
  84 struct ads7846_packet {
  85         u8                      read_x, read_y, read_z1, read_z2, pwrdown;
  86         u16                     dummy;          /* for the pwrdown read */
  87         struct ts_event         tc;
  88         /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
  89         u8                      read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
  90 };
  91
  92 struct ads7846 {
  93         struct input_dev        *input;
  94         char                    phys[32];
  95         char                    name[32];
  96
  97         struct spi_device       *spi;
  98         struct regulator        *reg;
  99
 100 #if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
 101         struct attribute_group  *attr_group;
 102         struct device           *hwmon;
 103 #endif
 104
 105         u16                     model;
 106         u16                     vref_mv;
 107         u16                     vref_delay_usecs;
 108         u16                     x_plate_ohms;
 109         u16                     pressure_max;
 110
 111         bool                    swap_xy;
 112         bool                    use_internal;
 113
 114         struct ads7846_packet   *packet;
 115
 116         struct spi_transfer     xfer[18];
 117         struct spi_message      msg[5];
 118         int                     msg_count;
 119         wait_queue_head_t       wait;
 120
 121         bool                    pendown;
 122
 123         int                     read_cnt;
 124         int                     read_rep;
 125         int                     last_read;
 126
 127         u16                     debounce_max;
 128         u16                     debounce_tol;
 129         u16                     debounce_rep;
 130
 131         u16                     penirq_recheck_delay_usecs;
 132
 133         struct mutex            lock;
 134         bool                    stopped;        /* P: lock */
 135         bool                    disabled;       /* P: lock */
 136         bool                    suspended;      /* P: lock */
 137
 138         int                     (*filter)(void *data, int data_idx, int *val);
 139         void                    *filter_data;
 140         void                    (*filter_cleanup)(void *data);
 141         int                     (*get_pendown_state)(void);
 142         int                     gpio_pendown;
 143
 144         void                    (*wait_for_sync)(void);
 145 };
 146
 147 /* leave chip selected when we're done, for quicker re-select? */
 148 #if     0
 149 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
 150 #else
 151 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
 152 #endif
 153
 154 /*--------------------------------------------------------------------------*/
 155
 156 /* The ADS7846 has touchscreen and other sensors.
 157  * Earlier ads784x chips are somewhat compatible.
 158  */
 159 #define ADS_START               (1 << 7)
 160 #define ADS_A2A1A0_d_y          (1 << 4)        /* differential */
 161 #define ADS_A2A1A0_d_z1         (3 << 4)        /* differential */
 162 #define ADS_A2A1A0_d_z2         (4 << 4)        /* differential */
 163 #define ADS_A2A1A0_d_x          (5 << 4)        /* differential */
 164 #define ADS_A2A1A0_temp0        (0 << 4)        /* non-differential */
 165 #define ADS_A2A1A0_vbatt        (2 << 4)        /* non-differential */
 166 #define ADS_A2A1A0_vaux         (6 << 4)        /* non-differential */
 167 #define ADS_A2A1A0_temp1        (7 << 4)        /* non-differential */
 168 #define ADS_8_BIT               (1 << 3)
 169 #define ADS_12_BIT              (0 << 3)
 170 #define ADS_SER                 (1 << 2)        /* non-differential */
 171 #define ADS_DFR                 (0 << 2)        /* differential */
 172 #define ADS_PD10_PDOWN          (0 << 0)        /* low power mode + penirq */
 173 #define ADS_PD10_ADC_ON         (1 << 0)        /* ADC on */
 174 #define ADS_PD10_REF_ON         (2 << 0)        /* vREF on + penirq */
 175 #define ADS_PD10_ALL_ON         (3 << 0)        /* ADC + vREF on */
 176
 177 #define MAX_12BIT       ((1<<12)-1)
 178
 179 /* leave ADC powered up (disables penirq) between differential samples */
 180 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
 181         | ADS_12_BIT | ADS_DFR | \
 182         (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
 183
 184 #define READ_Y(vref)    (READ_12BIT_DFR(y,  1, vref))
 185 #define READ_Z1(vref)   (READ_12BIT_DFR(z1, 1, vref))
 186 #define READ_Z2(vref)   (READ_12BIT_DFR(z2, 1, vref))
 187
 188 #define READ_X(vref)    (READ_12BIT_DFR(x,  1, vref))
 189 #define PWRDOWN         (READ_12BIT_DFR(y,  0, 0))      /* LAST */
 190
 191 /* single-ended samples need to first power up reference voltage;
 192  * we leave both ADC and VREF powered
 193  */
 194 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
 195         | ADS_12_BIT | ADS_SER)
 196
 197 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
 198 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 199
 200 /* Must be called with ts->lock held */
 201 static void ads7846_stop(struct ads7846 *ts)
 202 {
 203         if (!ts->disabled && !ts->suspended) {
 204                 /* Signal IRQ thread to stop polling and disable the handler. */
 205                 ts->stopped = true;
 206                 mb();
 207                 wake_up(&ts->wait);
 208                 disable_irq(ts->spi->irq);
 209         }
 210 }
 211
 212 /* Must be called with ts->lock held */
 213 static void ads7846_restart(struct ads7846 *ts)
 214 {
 215         if (!ts->disabled && !ts->suspended) {
 216                 /* Tell IRQ thread that it may poll the device. */
 217                 ts->stopped = false;
 218                 mb();
 219                 enable_irq(ts->spi->irq);
 220         }
 221 }
 222
 223 /* Must be called with ts->lock held */
 224 static void __ads7846_disable(struct ads7846 *ts)
 225 {
 226         ads7846_stop(ts);
 227         regulator_disable(ts->reg);
 228
 229         /*
 230          * We know the chip's in low power mode since we always
 231          * leave it that way after every request
 232          */
 233 }
 234
 235 /* Must be called with ts->lock held */
 236 static void __ads7846_enable(struct ads7846 *ts)
 237 {
 238         regulator_enable(ts->reg);
 239         ads7846_restart(ts);
 240 }
 241
 242 static void ads7846_disable(struct ads7846 *ts)
 243 {
 244         mutex_lock(&ts->lock);
 245
 246         if (!ts->disabled) {
 247
 248                 if  (!ts->suspended)
 249                         __ads7846_disable(ts);
 250
 251                 ts->disabled = true;
 252         }
 253
 254         mutex_unlock(&ts->lock);
 255 }
 256
 257 static void ads7846_enable(struct ads7846 *ts)
 258 {
 259         mutex_lock(&ts->lock);
 260
 261         if (ts->disabled) {
 262
 263                 ts->disabled = false;
 264
 265                 if (!ts->suspended)
 266                         __ads7846_enable(ts);
 267         }
 268
 269         mutex_unlock(&ts->lock);
 270 }
 271
 272 /*--------------------------------------------------------------------------*/
 273
 274 /*
 275  * Non-touchscreen sensors only use single-ended conversions.
 276  * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
 277  * ads7846 lets that pin be unconnected, to use internal vREF.
 278  */
 279
 280 struct ser_req {
 281         u8                      ref_on;
 282         u8                      command;
 283         u8                      ref_off;
 284         u16                     scratch;
 285         __be16                  sample;
 286         struct spi_message      msg;
 287         struct spi_transfer     xfer[6];
 288 };
 289
 290 struct ads7845_ser_req {
 291         u8                      command[3];
 292         u8                      pwrdown[3];
 293         u8                      sample[3];
 294         struct spi_message      msg;
 295         struct spi_transfer     xfer[2];
 296 };
 297
 298 static int ads7846_read12_ser(struct device *dev, unsigned command)
 299 {
 300         struct spi_device *spi = to_spi_device(dev);
 301         struct ads7846 *ts = dev_get_drvdata(dev);
 302         struct ser_req *req;
 303         int status;
 304
 305         req = kzalloc(sizeof *req, GFP_KERNEL);
 306         if (!req)
 307                 return -ENOMEM;
 308
 309         spi_message_init(&req->msg);
 310
 311         /* maybe turn on internal vREF, and let it settle */
 312         if (ts->use_internal) {
 313                 req->ref_on = REF_ON;
 314                 req->xfer[0].tx_buf = &req->ref_on;
 315                 req->xfer[0].len = 1;
 316                 spi_message_add_tail(&req->xfer[0], &req->msg);
 317
 318                 req->xfer[1].rx_buf = &req->scratch;
 319                 req->xfer[1].len = 2;
 320
 321                 /* for 1uF, settle for 800 usec; no cap, 100 usec.  */
 322                 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 323                 spi_message_add_tail(&req->xfer[1], &req->msg);
 324
 325                 /* Enable reference voltage */
 326                 command |= ADS_PD10_REF_ON;
 327         }
 328
 329         /* Enable ADC in every case */
 330         command |= ADS_PD10_ADC_ON;
 331
 332         /* take sample */
 333         req->command = (u8) command;
 334         req->xfer[2].tx_buf = &req->command;
 335         req->xfer[2].len = 1;
 336         spi_message_add_tail(&req->xfer[2], &req->msg);
 337
 338         req->xfer[3].rx_buf = &req->sample;
 339         req->xfer[3].len = 2;
 340         spi_message_add_tail(&req->xfer[3], &req->msg);
 341
 342         /* REVISIT:  take a few more samples, and compare ... */
 343
 344         /* converter in low power mode & enable PENIRQ */
 345         req->ref_off = PWRDOWN;
 346         req->xfer[4].tx_buf = &req->ref_off;
 347         req->xfer[4].len = 1;
 348         spi_message_add_tail(&req->xfer[4], &req->msg);
 349
 350         req->xfer[5].rx_buf = &req->scratch;
 351         req->xfer[5].len = 2;
 352         CS_CHANGE(req->xfer[5]);
 353         spi_message_add_tail(&req->xfer[5], &req->msg);
 354
 355         mutex_lock(&ts->lock);
 356         ads7846_stop(ts);
 357         status = spi_sync(spi, &req->msg);
 358         ads7846_restart(ts);
 359         mutex_unlock(&ts->lock);
 360
 361         if (status == 0) {
 362                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
 363                 status = be16_to_cpu(req->sample);
 364                 status = status >> 3;
 365                 status &= 0x0fff;
 366         }
 367
 368         kfree(req);
 369         return status;
 370 }
 371
 372 static int ads7845_read12_ser(struct device *dev, unsigned command)
 373 {
 374         struct spi_device *spi = to_spi_device(dev);
 375         struct ads7846 *ts = dev_get_drvdata(dev);
 376         struct ads7845_ser_req *req;
 377         int status;
 378
 379         req = kzalloc(sizeof *req, GFP_KERNEL);
 380         if (!req)
 381                 return -ENOMEM;
 382
 383         spi_message_init(&req->msg);
 384
 385         req->command[0] = (u8) command;
 386         req->xfer[0].tx_buf = req->command;
 387         req->xfer[0].rx_buf = req->sample;
 388         req->xfer[0].len = 3;
 389         spi_message_add_tail(&req->xfer[0], &req->msg);
 390
 391         mutex_lock(&ts->lock);
 392         ads7846_stop(ts);
 393         status = spi_sync(spi, &req->msg);
 394         ads7846_restart(ts);
 395         mutex_unlock(&ts->lock);
 396
 397         if (status == 0) {
 398                 /* BE12 value, then padding */
 399                 status = be16_to_cpu(*((u16 *)&req->sample[1]));
 400                 status = status >> 3;
 401                 status &= 0x0fff;
 402         }
 403
 404         kfree(req);
 405         return status;
 406 }
 407
 408 #if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
 409
 410 #define SHOW(name, var, adjust) static ssize_t \
 411 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 412 { \
 413         struct ads7846 *ts = dev_get_drvdata(dev); \
 414         ssize_t v = ads7846_read12_ser(dev, \
 415                         READ_12BIT_SER(var)); \
 416         if (v < 0) \
 417                 return v; \
 418         return sprintf(buf, "%u\n", adjust(ts, v)); \
 419 } \
 420 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 421
 422
 423 /* Sysfs conventions report temperatures in millidegrees Celsius.
 424  * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
 425  * accuracy scheme without calibration data.  For now we won't try either;
 426  * userspace sees raw sensor values, and must scale/calibrate appropriately.
 427  */
 428 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
 429 {
 430         return v;
 431 }
 432
 433 SHOW(temp0, temp0, null_adjust)         /* temp1_input */
 434 SHOW(temp1, temp1, null_adjust)         /* temp2_input */
 435
 436
 437 /* sysfs conventions report voltages in millivolts.  We can convert voltages
 438  * if we know vREF.  userspace may need to scale vAUX to match the board's
 439  * external resistors; we assume that vBATT only uses the internal ones.
 440  */
 441 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
 442 {
 443         unsigned retval = v;
 444
 445         /* external resistors may scale vAUX into 0..vREF */
 446         retval *= ts->vref_mv;
 447         retval = retval >> 12;
 448
 449         return retval;
 450 }
 451
 452 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
 453 {
 454         unsigned retval = vaux_adjust(ts, v);
 455
 456         /* ads7846 has a resistor ladder to scale this signal down */
 457         if (ts->model == 7846)
 458                 retval *= 4;
 459
 460         return retval;
 461 }
 462
 463 SHOW(in0_input, vaux, vaux_adjust)
 464 SHOW(in1_input, vbatt, vbatt_adjust)
 465
 466 static struct attribute *ads7846_attributes[] = {
 467         &dev_attr_temp0.attr,
 468         &dev_attr_temp1.attr,
 469         &dev_attr_in0_input.attr,
 470         &dev_attr_in1_input.attr,
 471         NULL,
 472 };
 473
 474 static struct attribute_group ads7846_attr_group = {
 475         .attrs = ads7846_attributes,
 476 };
 477
 478 static struct attribute *ads7843_attributes[] = {
 479         &dev_attr_in0_input.attr,
 480         &dev_attr_in1_input.attr,
 481         NULL,
 482 };
 483
 484 static struct attribute_group ads7843_attr_group = {
 485         .attrs = ads7843_attributes,
 486 };
 487
 488 static struct attribute *ads7845_attributes[] = {
 489         &dev_attr_in0_input.attr,
 490         NULL,
 491 };
 492
 493 static struct attribute_group ads7845_attr_group = {
 494         .attrs = ads7845_attributes,
 495 };
 496
 497 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 498 {
 499         struct device *hwmon;
 500         int err;
 501
 502         /* hwmon sensors need a reference voltage */
 503         switch (ts->model) {
 504         case 7846:
 505                 if (!ts->vref_mv) {
 506                         dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
 507                         ts->vref_mv = 2500;
 508                         ts->use_internal = true;
 509                 }
 510                 break;
 511         case 7845:
 512         case 7843:
 513                 if (!ts->vref_mv) {
 514                         dev_warn(&spi->dev,
 515                                 "external vREF for ADS%d not specified\n",
 516                                 ts->model);
 517                         return 0;
 518                 }
 519                 break;
 520         }
 521
 522         /* different chips have different sensor groups */
 523         switch (ts->model) {
 524         case 7846:
 525                 ts->attr_group = &ads7846_attr_group;
 526                 break;
 527         case 7845:
 528                 ts->attr_group = &ads7845_attr_group;
 529                 break;
 530         case 7843:
 531                 ts->attr_group = &ads7843_attr_group;
 532                 break;
 533         default:
 534                 dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model);
 535                 return 0;
 536         }
 537
 538         err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
 539         if (err)
 540                 return err;
 541
 542         hwmon = hwmon_device_register(&spi->dev);
 543         if (IS_ERR(hwmon)) {
 544                 sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
 545                 return PTR_ERR(hwmon);
 546         }
 547
 548         ts->hwmon = hwmon;
 549         return 0;
 550 }
 551
 552 static void ads784x_hwmon_unregister(struct spi_device *spi,
 553                                      struct ads7846 *ts)
 554 {
 555         if (ts->hwmon) {
 556                 sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
 557                 hwmon_device_unregister(ts->hwmon);
 558         }
 559 }
 560
 561 #else
 562 static inline int ads784x_hwmon_register(struct spi_device *spi,
 563                                          struct ads7846 *ts)
 564 {
 565         return 0;
 566 }
 567
 568 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
 569                                             struct ads7846 *ts)
 570 {
 571 }
 572 #endif
 573
 574 static ssize_t ads7846_pen_down_show(struct device *dev,
 575                                      struct device_attribute *attr, char *buf)
 576 {
 577         struct ads7846 *ts = dev_get_drvdata(dev);
 578
 579         return sprintf(buf, "%u\n", ts->pendown);
 580 }
 581
 582 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
 583
 584 static ssize_t ads7846_disable_show(struct device *dev,
 585                                      struct device_attribute *attr, char *buf)
 586 {
 587         struct ads7846 *ts = dev_get_drvdata(dev);
 588
 589         return sprintf(buf, "%u\n", ts->disabled);
 590 }
 591
 592 static ssize_t ads7846_disable_store(struct device *dev,
 593                                      struct device_attribute *attr,
 594                                      const char *buf, size_t count)
 595 {
 596         struct ads7846 *ts = dev_get_drvdata(dev);
 597         unsigned long i;
 598
 599         if (strict_strtoul(buf, 10, &i))
 600                 return -EINVAL;
 601
 602         if (i)
 603                 ads7846_disable(ts);
 604         else
 605                 ads7846_enable(ts);
 606
 607         return count;
 608 }
 609
 610 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 611
 612 static struct attribute *ads784x_attributes[] = {
 613         &dev_attr_pen_down.attr,
 614         &dev_attr_disable.attr,
 615         NULL,
 616 };
 617
 618 static struct attribute_group ads784x_attr_group = {
 619         .attrs = ads784x_attributes,
 620 };
 621
 622 /*--------------------------------------------------------------------------*/
 623
 624 static int get_pendown_state(struct ads7846 *ts)
 625 {
 626         if (ts->get_pendown_state)
 627                 return ts->get_pendown_state();
 628
 629         return !gpio_get_value(ts->gpio_pendown);
 630 }
 631
 632 static void null_wait_for_sync(void)
 633 {
 634 }
 635
 636 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
 637 {
 638         struct ads7846 *ts = ads;
 639
 640         if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 641                 /* Start over collecting consistent readings. */
 642                 ts->read_rep = 0;
 643                 /*
 644                  * Repeat it, if this was the first read or the read
 645                  * wasn't consistent enough.
 646                  */
 647                 if (ts->read_cnt < ts->debounce_max) {
 648                         ts->last_read = *val;
 649                         ts->read_cnt++;
 650                         return ADS7846_FILTER_REPEAT;
 651                 } else {
 652                         /*
 653                          * Maximum number of debouncing reached and still
 654                          * not enough number of consistent readings. Abort
 655                          * the whole sample, repeat it in the next sampling
 656                          * period.
 657                          */
 658                         ts->read_cnt = 0;
 659                         return ADS7846_FILTER_IGNORE;
 660                 }
 661         } else {
 662                 if (++ts->read_rep > ts->debounce_rep) {
 663                         /*
 664                          * Got a good reading for this coordinate,
 665                          * go for the next one.
 666                          */
 667                         ts->read_cnt = 0;
 668                         ts->read_rep = 0;
 669                         return ADS7846_FILTER_OK;
 670                 } else {
 671                         /* Read more values that are consistent. */
 672                         ts->read_cnt++;
 673                         return ADS7846_FILTER_REPEAT;
 674                 }
 675         }
 676 }
 677
 678 static int ads7846_no_filter(void *ads, int data_idx, int *val)
 679 {
 680         return ADS7846_FILTER_OK;
 681 }
 682
 683 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
 684 {
 685         struct spi_transfer *t =
 686                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 687
 688         if (ts->model == 7845) {
 689                 return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3;
 690         } else {
 691                 /*
 692                  * adjust:  on-wire is a must-ignore bit, a BE12 value, then
 693                  * padding; built from two 8 bit values written msb-first.
 694                  */
 695                 return be16_to_cpup((__be16 *)t->rx_buf) >> 3;
 696         }
 697 }
 698
 699 static void ads7846_update_value(struct spi_message *m, int val)
 700 {
 701         struct spi_transfer *t =
 702                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 703
 704         *(u16 *)t->rx_buf = val;
 705 }
 706
 707 static void ads7846_read_state(struct ads7846 *ts)
 708 {
 709         struct ads7846_packet *packet = ts->packet;
 710         struct spi_message *m;
 711         int msg_idx = 0;
 712         int val;
 713         int action;
 714         int error;
 715
 716         while (msg_idx < ts->msg_count) {
 717
 718                 ts->wait_for_sync();
 719
 720                 m = &ts->msg[msg_idx];
 721                 error = spi_sync(ts->spi, m);
 722                 if (error) {
 723                         dev_err(&ts->spi->dev, "spi_async --> %d\n", error);
 724                         packet->tc.ignore = true;
 725                         return;
 726                 }
 727
 728                 /*
 729                  * Last message is power down request, no need to convert
 730                  * or filter the value.
 731                  */
 732                 if (msg_idx < ts->msg_count - 1) {
 733
 734                         val = ads7846_get_value(ts, m);
 735
 736                         action = ts->filter(ts->filter_data, msg_idx, &val);
 737                         switch (action) {
 738                         case ADS7846_FILTER_REPEAT:
 739                                 continue;
 740
 741                         case ADS7846_FILTER_IGNORE:
 742                                 packet->tc.ignore = true;
 743                                 msg_idx = ts->msg_count - 1;
 744                                 continue;
 745
 746                         case ADS7846_FILTER_OK:
 747                                 ads7846_update_value(m, val);
 748                                 packet->tc.ignore = false;
 749                                 msg_idx++;
 750                                 break;
 751
 752                         default:
 753                                 BUG();
 754                         }
 755                 } else {
 756                         msg_idx++;
 757                 }
 758         }
 759 }
 760
 761 static void ads7846_report_state(struct ads7846 *ts)
 762 {
 763         struct ads7846_packet *packet = ts->packet;
 764         unsigned int Rt;
 765         u16 x, y, z1, z2;
 766
 767         /*
 768          * ads7846_get_value() does in-place conversion (including byte swap)
 769          * from on-the-wire format as part of debouncing to get stable
 770          * readings.
 771          */
 772         if (ts->model == 7845) {
 773                 x = *(u16 *)packet->tc.x_buf;
 774                 y = *(u16 *)packet->tc.y_buf;
 775                 z1 = 0;
 776                 z2 = 0;
 777         } else {
 778                 x = packet->tc.x;
 779                 y = packet->tc.y;
 780                 z1 = packet->tc.z1;
 781                 z2 = packet->tc.z2;
 782         }
 783
 784         /* range filtering */
 785         if (x == MAX_12BIT)
 786                 x = 0;
 787
 788         if (ts->model == 7843) {
 789                 Rt = ts->pressure_max / 2;
 790         } else if (ts->model == 7845) {
 791                 if (get_pendown_state(ts))
 792                         Rt = ts->pressure_max / 2;
 793                 else
 794                         Rt = 0;
 795                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 796         } else if (likely(x && z1)) {
 797                 /* compute touch pressure resistance using equation #2 */
 798                 Rt = z2;
 799                 Rt -= z1;
 800                 Rt *= x;
 801                 Rt *= ts->x_plate_ohms;
 802                 Rt /= z1;
 803                 Rt = (Rt + 2047) >> 12;
 804         } else {
 805                 Rt = 0;
 806         }
 807
 808         /*
 809          * Sample found inconsistent by debouncing or pressure is beyond
 810          * the maximum. Don't report it to user space, repeat at least
 811          * once more the measurement
 812          */
 813         if (packet->tc.ignore || Rt > ts->pressure_max) {
 814                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 815                          packet->tc.ignore, Rt);
 816                 return;
 817         }
 818
 819         /*
 820          * Maybe check the pendown state before reporting. This discards
 821          * false readings when the pen is lifted.
 822          */
 823         if (ts->penirq_recheck_delay_usecs) {
 824                 udelay(ts->penirq_recheck_delay_usecs);
 825                 if (!get_pendown_state(ts))
 826                         Rt = 0;
 827         }
 828
 829         /*
 830          * NOTE: We can't rely on the pressure to determine the pen down
 831          * state, even this controller has a pressure sensor. The pressure
 832          * value can fluctuate for quite a while after lifting the pen and
 833          * in some cases may not even settle at the expected value.
 834          *
 835          * The only safe way to check for the pen up condition is in the
 836          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 837          */
 838         if (Rt) {
 839                 struct input_dev *input = ts->input;
 840
 841                 if (ts->swap_xy)
 842                         swap(x, y);
 843
 844                 if (!ts->pendown) {
 845                         input_report_key(input, BTN_TOUCH, 1);
 846                         ts->pendown = true;
 847                         dev_vdbg(&ts->spi->dev, "DOWN\n");
 848                 }
 849
 850                 input_report_abs(input, ABS_X, x);
 851                 input_report_abs(input, ABS_Y, y);
 852                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 853
 854                 input_sync(input);
 855                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
 856         }
 857 }
 858
 859 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 860 {
 861         struct ads7846 *ts = handle;
 862
 863         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 864 }
 865
 866
 867 static irqreturn_t ads7846_irq(int irq, void *handle)
 868 {
 869         struct ads7846 *ts = handle;
 870
 871         /* Start with a small delay before checking pendown state */
 872         msleep(TS_POLL_DELAY);
 873
 874         while (!ts->stopped && get_pendown_state(ts)) {
 875
 876                 /* pen is down, continue with the measurement */
 877                 ads7846_read_state(ts);
 878
 879                 if (!ts->stopped)
 880                         ads7846_report_state(ts);
 881
 882                 wait_event_timeout(ts->wait, ts->stopped,
 883                                    msecs_to_jiffies(TS_POLL_PERIOD));
 884         }
 885
 886         if (ts->pendown) {
 887                 struct input_dev *input = ts->input;
 888
 889                 input_report_key(input, BTN_TOUCH, 0);
 890                 input_report_abs(input, ABS_PRESSURE, 0);
 891                 input_sync(input);
 892
 893                 ts->pendown = false;
 894                 dev_vdbg(&ts->spi->dev, "UP\n");
 895         }
 896
 897         return IRQ_HANDLED;
 898 }
 899
 900 #ifdef CONFIG_PM_SLEEP
 901 static int ads7846_suspend(struct device *dev)
 902 {
 903         struct ads7846 *ts = dev_get_drvdata(dev);
 904
 905         mutex_lock(&ts->lock);
 906
 907         if (!ts->suspended) {
 908
 909                 if (!ts->disabled)
 910                         __ads7846_disable(ts);
 911
 912                 if (device_may_wakeup(&ts->spi->dev))
 913                         enable_irq_wake(ts->spi->irq);
 914
 915                 ts->suspended = true;
 916         }
 917
 918         mutex_unlock(&ts->lock);
 919
 920         return 0;
 921 }
 922
 923 static int ads7846_resume(struct device *dev)
 924 {
 925         struct ads7846 *ts = dev_get_drvdata(dev);
 926
 927         mutex_lock(&ts->lock);
 928
 929         if (ts->suspended) {
 930
 931                 ts->suspended = false;
 932
 933                 if (device_may_wakeup(&ts->spi->dev))
 934                         disable_irq_wake(ts->spi->irq);
 935
 936                 if (!ts->disabled)
 937                         __ads7846_enable(ts);
 938         }
 939
 940         mutex_unlock(&ts->lock);
 941
 942         return 0;
 943 }
 944 #endif
 945
 946 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 947
 948 static int __devinit ads7846_setup_pendown(struct spi_device *spi, struct ads7846 *ts)
 949 {
 950         struct ads7846_platform_data *pdata = spi->dev.platform_data;
 951         int err;
 952
 953         /*
 954          * REVISIT when the irq can be triggered active-low, or if for some
 955          * reason the touchscreen isn't hooked up, we don't need to access
 956          * the pendown state.
 957          */
 958
 959         if (pdata->get_pendown_state) {
 960                 ts->get_pendown_state = pdata->get_pendown_state;
 961         } else if (gpio_is_valid(pdata->gpio_pendown)) {
 962
 963                 err = gpio_request(pdata->gpio_pendown, "ads7846_pendown");
 964                 if (err) {
 965                         dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
 966                                 pdata->gpio_pendown);
 967                         return err;
 968                 }
 969                 err = gpio_direction_input(pdata->gpio_pendown);
 970                 if (err) {
 971                         dev_err(&spi->dev, "failed to setup pendown GPIO%d\n",
 972                                 pdata->gpio_pendown);
 973                         gpio_free(pdata->gpio_pendown);
 974                         return err;
 975                 }
 976
 977                 ts->gpio_pendown = pdata->gpio_pendown;
 978
 979         } else {
 980                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 981                 return -EINVAL;
 982         }
 983
 984         return 0;
 985 }
 986
 987 /*
 988  * Set up the transfers to read touchscreen state; this assumes we
 989  * use formula #2 for pressure, not #3.
 990  */
 991 static void __devinit ads7846_setup_spi_msg(struct ads7846 *ts,
 992                                 const struct ads7846_platform_data *pdata)
 993 {
 994         struct spi_message *m = &ts->msg[0];
 995         struct spi_transfer *x = ts->xfer;
 996         struct ads7846_packet *packet = ts->packet;
 997         int vref = pdata->keep_vref_on;
 998
 999         if (ts->model == 7873) {
1000                 /*
1001                  * The AD7873 is almost identical to the ADS7846
1002                  * keep VREF off during differential/ratiometric
1003                  * conversion modes.
1004                  */
1005                 ts->model = 7846;
1006                 vref = 0;
1007         }
1008
1009         ts->msg_count = 1;
1010         spi_message_init(m);
1011         m->context = ts;
1012
1013         if (ts->model == 7845) {
1014                 packet->read_y_cmd[0] = READ_Y(vref);
1015                 packet->read_y_cmd[1] = 0;
1016                 packet->read_y_cmd[2] = 0;
1017                 x->tx_buf = &packet->read_y_cmd[0];
1018                 x->rx_buf = &packet->tc.y_buf[0];
1019                 x->len = 3;
1020                 spi_message_add_tail(x, m);
1021         } else {
1022                 /* y- still on; turn on only y+ (and ADC) */
1023                 packet->read_y = READ_Y(vref);
1024                 x->tx_buf = &packet->read_y;
1025                 x->len = 1;
1026                 spi_message_add_tail(x, m);
1027
1028                 x++;
1029                 x->rx_buf = &packet->tc.y;
1030                 x->len = 2;
1031                 spi_message_add_tail(x, m);
1032         }
1033
1034         /*
1035          * The first sample after switching drivers can be low quality;
1036          * optionally discard it, using a second one after the signals
1037          * have had enough time to stabilize.
1038          */
1039         if (pdata->settle_delay_usecs) {
1040                 x->delay_usecs = pdata->settle_delay_usecs;
1041
1042                 x++;
1043                 x->tx_buf = &packet->read_y;
1044                 x->len = 1;
1045                 spi_message_add_tail(x, m);
1046
1047                 x++;
1048                 x->rx_buf = &packet->tc.y;
1049                 x->len = 2;
1050                 spi_message_add_tail(x, m);
1051         }
1052
1053         ts->msg_count++;
1054         m++;
1055         spi_message_init(m);
1056         m->context = ts;
1057
1058         if (ts->model == 7845) {
1059                 x++;
1060                 packet->read_x_cmd[0] = READ_X(vref);
1061                 packet->read_x_cmd[1] = 0;
1062                 packet->read_x_cmd[2] = 0;
1063                 x->tx_buf = &packet->read_x_cmd[0];
1064                 x->rx_buf = &packet->tc.x_buf[0];
1065                 x->len = 3;
1066                 spi_message_add_tail(x, m);
1067         } else {
1068                 /* turn y- off, x+ on, then leave in lowpower */
1069                 x++;
1070                 packet->read_x = READ_X(vref);
1071                 x->tx_buf = &packet->read_x;
1072                 x->len = 1;
1073                 spi_message_add_tail(x, m);
1074
1075                 x++;
1076                 x->rx_buf = &packet->tc.x;
1077                 x->len = 2;
1078                 spi_message_add_tail(x, m);
1079         }
1080
1081         /* ... maybe discard first sample ... */
1082         if (pdata->settle_delay_usecs) {
1083                 x->delay_usecs = pdata->settle_delay_usecs;
1084
1085                 x++;
1086                 x->tx_buf = &packet->read_x;
1087                 x->len = 1;
1088                 spi_message_add_tail(x, m);
1089
1090                 x++;
1091                 x->rx_buf = &packet->tc.x;
1092                 x->len = 2;
1093                 spi_message_add_tail(x, m);
1094         }
1095
1096         /* turn y+ off, x- on; we'll use formula #2 */
1097         if (ts->model == 7846) {
1098                 ts->msg_count++;
1099                 m++;
1100                 spi_message_init(m);
1101                 m->context = ts;
1102
1103                 x++;
1104                 packet->read_z1 = READ_Z1(vref);
1105                 x->tx_buf = &packet->read_z1;
1106                 x->len = 1;
1107                 spi_message_add_tail(x, m);
1108
1109                 x++;
1110                 x->rx_buf = &packet->tc.z1;
1111                 x->len = 2;
1112                 spi_message_add_tail(x, m);
1113
1114                 /* ... maybe discard first sample ... */
1115                 if (pdata->settle_delay_usecs) {
1116                         x->delay_usecs = pdata->settle_delay_usecs;
1117
1118                         x++;
1119                         x->tx_buf = &packet->read_z1;
1120                         x->len = 1;
1121                         spi_message_add_tail(x, m);
1122
1123                         x++;
1124                         x->rx_buf = &packet->tc.z1;
1125                         x->len = 2;
1126                         spi_message_add_tail(x, m);
1127                 }
1128
1129                 ts->msg_count++;
1130                 m++;
1131                 spi_message_init(m);
1132                 m->context = ts;
1133
1134                 x++;
1135                 packet->read_z2 = READ_Z2(vref);
1136                 x->tx_buf = &packet->read_z2;
1137                 x->len = 1;
1138                 spi_message_add_tail(x, m);
1139
1140                 x++;
1141                 x->rx_buf = &packet->tc.z2;
1142                 x->len = 2;
1143                 spi_message_add_tail(x, m);
1144
1145                 /* ... maybe discard first sample ... */
1146                 if (pdata->settle_delay_usecs) {
1147                         x->delay_usecs = pdata->settle_delay_usecs;
1148
1149                         x++;
1150                         x->tx_buf = &packet->read_z2;
1151                         x->len = 1;
1152                         spi_message_add_tail(x, m);
1153
1154                         x++;
1155                         x->rx_buf = &packet->tc.z2;
1156                         x->len = 2;
1157                         spi_message_add_tail(x, m);
1158                 }
1159         }
1160
1161         /* power down */
1162         ts->msg_count++;
1163         m++;
1164         spi_message_init(m);
1165         m->context = ts;
1166
1167         if (ts->model == 7845) {
1168                 x++;
1169                 packet->pwrdown_cmd[0] = PWRDOWN;
1170                 packet->pwrdown_cmd[1] = 0;
1171                 packet->pwrdown_cmd[2] = 0;
1172                 x->tx_buf = &packet->pwrdown_cmd[0];
1173                 x->len = 3;
1174         } else {
1175                 x++;
1176                 packet->pwrdown = PWRDOWN;
1177                 x->tx_buf = &packet->pwrdown;
1178                 x->len = 1;
1179                 spi_message_add_tail(x, m);
1180
1181                 x++;
1182                 x->rx_buf = &packet->dummy;
1183                 x->len = 2;
1184         }
1185
1186         CS_CHANGE(*x);
1187         spi_message_add_tail(x, m);
1188 }
1189
1190 static int __devinit ads7846_probe(struct spi_device *spi)
1191 {
1192         struct ads7846 *ts;
1193         struct ads7846_packet *packet;
1194         struct input_dev *input_dev;
1195         struct ads7846_platform_data *pdata = spi->dev.platform_data;
1196         unsigned long irq_flags;
1197         int err;
1198
1199         if (!spi->irq) {
1200                 dev_dbg(&spi->dev, "no IRQ?\n");
1201                 return -ENODEV;
1202         }
1203
1204         if (!pdata) {
1205                 dev_dbg(&spi->dev, "no platform data?\n");
1206                 return -ENODEV;
1207         }
1208
1209         /* don't exceed max specified sample rate */
1210         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1211                 dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
1212                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1213                 return -EINVAL;
1214         }
1215
1216         /* We'd set TX word size 8 bits and RX word size to 13 bits ... except
1217          * that even if the hardware can do that, the SPI controller driver
1218          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1219          */
1220         spi->bits_per_word = 8;
1221         spi->mode = SPI_MODE_0;
1222         err = spi_setup(spi);
1223         if (err < 0)
1224                 return err;
1225
1226         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1227         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1228         input_dev = input_allocate_device();
1229         if (!ts || !packet || !input_dev) {
1230                 err = -ENOMEM;
1231                 goto err_free_mem;
1232         }
1233
1234         dev_set_drvdata(&spi->dev, ts);
1235
1236         ts->packet = packet;
1237         ts->spi = spi;
1238         ts->input = input_dev;
1239         ts->vref_mv = pdata->vref_mv;
1240         ts->swap_xy = pdata->swap_xy;
1241
1242         mutex_init(&ts->lock);
1243         init_waitqueue_head(&ts->wait);
1244
1245         ts->model = pdata->model ? : 7846;
1246         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1247         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1248         ts->pressure_max = pdata->pressure_max ? : ~0;
1249
1250         if (pdata->filter != NULL) {
1251                 if (pdata->filter_init != NULL) {
1252                         err = pdata->filter_init(pdata, &ts->filter_data);
1253                         if (err < 0)
1254                                 goto err_free_mem;
1255                 }
1256                 ts->filter = pdata->filter;
1257                 ts->filter_cleanup = pdata->filter_cleanup;
1258         } else if (pdata->debounce_max) {
1259                 ts->debounce_max = pdata->debounce_max;
1260                 if (ts->debounce_max < 2)
1261                         ts->debounce_max = 2;
1262                 ts->debounce_tol = pdata->debounce_tol;
1263                 ts->debounce_rep = pdata->debounce_rep;
1264                 ts->filter = ads7846_debounce_filter;
1265                 ts->filter_data = ts;
1266         } else {
1267                 ts->filter = ads7846_no_filter;
1268         }
1269
1270         err = ads7846_setup_pendown(spi, ts);
1271         if (err)
1272                 goto err_cleanup_filter;
1273
1274         if (pdata->penirq_recheck_delay_usecs)
1275                 ts->penirq_recheck_delay_usecs =
1276                                 pdata->penirq_recheck_delay_usecs;
1277
1278         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1279
1280         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1281         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1282
1283         input_dev->name = ts->name;
1284         input_dev->phys = ts->phys;
1285         input_dev->dev.parent = &spi->dev;
1286
1287         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1288         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1289         input_set_abs_params(input_dev, ABS_X,
1290                         pdata->x_min ? : 0,
1291                         pdata->x_max ? : MAX_12BIT,
1292                         0, 0);
1293         input_set_abs_params(input_dev, ABS_Y,
1294                         pdata->y_min ? : 0,
1295                         pdata->y_max ? : MAX_12BIT,
1296                         0, 0);
1297         input_set_abs_params(input_dev, ABS_PRESSURE,
1298                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1299
1300         ads7846_setup_spi_msg(ts, pdata);
1301
1302         ts->reg = regulator_get(&spi->dev, "vcc");
1303         if (IS_ERR(ts->reg)) {
1304                 err = PTR_ERR(ts->reg);
1305                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1306                 goto err_free_gpio;
1307         }
1308
1309         err = regulator_enable(ts->reg);
1310         if (err) {
1311                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1312                 goto err_put_regulator;
1313         }
1314
1315         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1316         irq_flags |= IRQF_ONESHOT;
1317
1318         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1319                                    irq_flags, spi->dev.driver->name, ts);
1320         if (err && !pdata->irq_flags) {
1321                 dev_info(&spi->dev,
1322                         "trying pin change workaround on irq %d\n", spi->irq);
1323                 irq_flags |= IRQF_TRIGGER_RISING;
1324                 err = request_threaded_irq(spi->irq,
1325                                   ads7846_hard_irq, ads7846_irq,
1326                                   irq_flags, spi->dev.driver->name, ts);
1327         }
1328
1329         if (err) {
1330                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1331                 goto err_disable_regulator;
1332         }
1333
1334         err = ads784x_hwmon_register(spi, ts);
1335         if (err)
1336                 goto err_free_irq;
1337
1338         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1339
1340         /*
1341          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1342          * the touchscreen, in case it's not connected.
1343          */
1344         if (ts->model == 7845)
1345                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1346         else
1347                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1348
1349         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1350         if (err)
1351                 goto err_remove_hwmon;
1352
1353         err = input_register_device(input_dev);
1354         if (err)
1355                 goto err_remove_attr_group;
1356
1357         device_init_wakeup(&spi->dev, pdata->wakeup);
1358
1359         return 0;
1360
1361  err_remove_attr_group:
1362         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1363  err_remove_hwmon:
1364         ads784x_hwmon_unregister(spi, ts);
1365  err_free_irq:
1366         free_irq(spi->irq, ts);
1367  err_disable_regulator:
1368         regulator_disable(ts->reg);
1369  err_put_regulator:
1370         regulator_put(ts->reg);
1371  err_free_gpio:
1372         if (!ts->get_pendown_state)
1373                 gpio_free(ts->gpio_pendown);
1374  err_cleanup_filter:
1375         if (ts->filter_cleanup)
1376                 ts->filter_cleanup(ts->filter_data);
1377  err_free_mem:
1378         input_free_device(input_dev);
1379         kfree(packet);
1380         kfree(ts);
1381         return err;
1382 }
1383
1384 static int __devexit ads7846_remove(struct spi_device *spi)
1385 {
1386         struct ads7846 *ts = dev_get_drvdata(&spi->dev);
1387
1388         device_init_wakeup(&spi->dev, false);
1389
1390         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1391
1392         ads7846_disable(ts);
1393         free_irq(ts->spi->irq, ts);
1394
1395         input_unregister_device(ts->input);
1396
1397         ads784x_hwmon_unregister(spi, ts);
1398
1399         regulator_disable(ts->reg);
1400         regulator_put(ts->reg);
1401
1402         if (!ts->get_pendown_state) {
1403                 /*
1404                  * If we are not using specialized pendown method we must
1405                  * have been relying on gpio we set up ourselves.
1406                  */
1407                 gpio_free(ts->gpio_pendown);
1408         }
1409
1410         if (ts->filter_cleanup)
1411                 ts->filter_cleanup(ts->filter_data);
1412
1413         kfree(ts->packet);
1414         kfree(ts);
1415
1416         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1417
1418         return 0;
1419 }
1420
1421 static struct spi_driver ads7846_driver = {
1422         .driver = {
1423                 .name   = "ads7846",
1424                 .bus    = &spi_bus_type,
1425                 .owner  = THIS_MODULE,
1426                 .pm     = &ads7846_pm,
1427         },
1428         .probe          = ads7846_probe,
1429         .remove         = __devexit_p(ads7846_remove),
1430 };
1431
1432 static int __init ads7846_init(void)
1433 {
1434         return spi_register_driver(&ads7846_driver);
1435 }
1436 module_init(ads7846_init);
1437
1438 static void __exit ads7846_exit(void)
1439 {
1440         spi_unregister_driver(&ads7846_driver);
1441 }
1442 module_exit(ads7846_exit);
1443
1444 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1445 MODULE_LICENSE("GPL");
1446 MODULE_ALIAS("spi:ads7846");