drivers/input/touchscreen/ads7846.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ADS7846 based touchscreen and sensor driver
   4  *
   5  * Copyright (c) 2005 David Brownell
   6  * Copyright (c) 2006 Nokia Corporation
   7  * Various changes: Imre Deak <imre.deak@nokia.com>
   8  *
   9  * Using code from:
  10  *  - corgi_ts.c
  11  *      Copyright (C) 2004-2005 Richard Purdie
  12  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  13  *      Copyright (C) 2002 MontaVista Software
  14  *      Copyright (C) 2004 Texas Instruments
  15  *      Copyright (C) 2005 Dirk Behme
  16  */
  17 #include <linux/types.h>
  18 #include <linux/hwmon.h>
  19 #include <linux/err.h>
  20 #include <linux/sched.h>
  21 #include <linux/delay.h>
  22 #include <linux/input.h>
  23 #include <linux/input/touchscreen.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/slab.h>
  26 #include <linux/pm.h>
  27 #include <linux/of.h>
  28 #include <linux/of_gpio.h>
  29 #include <linux/of_device.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 <linux/module.h>
  35 #include <asm/irq.h>
  36
  37 /*
  38  * This code has been heavily tested on a Nokia 770, and lightly
  39  * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
  40  * TSC2046 is just newer ads7846 silicon.
  41  * Support for ads7843 tested on Atmel at91sam926x-EK.
  42  * Support for ads7845 has only been stubbed in.
  43  * Support for Analog Devices AD7873 and AD7843 tested.
  44  *
  45  * IRQ handling needs a workaround because of a shortcoming in handling
  46  * edge triggered IRQs on some platforms like the OMAP1/2. These
  47  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
  48  * have to maintain our own SW IRQ disabled status. This should be
  49  * removed as soon as the affected platform's IRQ handling is fixed.
  50  *
  51  * App note sbaa036 talks in more detail about accurate sampling...
  52  * that ought to help in situations like LCDs inducing noise (which
  53  * can also be helped by using synch signals) and more generally.
  54  * This driver tries to utilize the measures described in the app
  55  * note. The strength of filtering can be set in the board-* specific
  56  * files.
  57  */
  58
  59 #define TS_POLL_DELAY   1       /* ms delay before the first sample */
  60 #define TS_POLL_PERIOD  5       /* ms delay between samples */
  61
  62 /* this driver doesn't aim at the peak continuous sample rate */
  63 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
  64
  65 struct ts_event {
  66         /*
  67          * For portability, we can't read 12 bit values using SPI (which
  68          * would make the controller deliver them as native byte order u16
  69          * with msbs zeroed).  Instead, we read them as two 8-bit values,
  70          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
  71          */
  72         u16     x;
  73         u16     y;
  74         u16     z1, z2;
  75         bool    ignore;
  76         u8      x_buf[3];
  77         u8      y_buf[3];
  78 };
  79
  80 /*
  81  * We allocate this separately to avoid cache line sharing issues when
  82  * driver is used with DMA-based SPI controllers (like atmel_spi) on
  83  * systems where main memory is not DMA-coherent (most non-x86 boards).
  84  */
  85 struct ads7846_packet {
  86         u8                      read_x, read_y, read_z1, read_z2, pwrdown;
  87         u16                     dummy;          /* for the pwrdown read */
  88         struct ts_event         tc;
  89         /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
  90         u8                      read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
  91 };
  92
  93 struct ads7846 {
  94         struct input_dev        *input;
  95         char                    phys[32];
  96         char                    name[32];
  97
  98         struct spi_device       *spi;
  99         struct regulator        *reg;
 100
 101 #if IS_ENABLED(CONFIG_HWMON)
 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 touchscreen_properties core_prop;
 134
 135         struct mutex            lock;
 136         bool                    stopped;        /* P: lock */
 137         bool                    disabled;       /* P: lock */
 138         bool                    suspended;      /* P: lock */
 139
 140         int                     (*filter)(void *data, int data_idx, int *val);
 141         void                    *filter_data;
 142         void                    (*filter_cleanup)(void *data);
 143         int                     (*get_pendown_state)(void);
 144         int                     gpio_pendown;
 145
 146         void                    (*wait_for_sync)(void);
 147 };
 148
 149 /* leave chip selected when we're done, for quicker re-select? */
 150 #if     0
 151 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
 152 #else
 153 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
 154 #endif
 155
 156 /*--------------------------------------------------------------------------*/
 157
 158 /* The ADS7846 has touchscreen and other sensors.
 159  * Earlier ads784x chips are somewhat compatible.
 160  */
 161 #define ADS_START               (1 << 7)
 162 #define ADS_A2A1A0_d_y          (1 << 4)        /* differential */
 163 #define ADS_A2A1A0_d_z1         (3 << 4)        /* differential */
 164 #define ADS_A2A1A0_d_z2         (4 << 4)        /* differential */
 165 #define ADS_A2A1A0_d_x          (5 << 4)        /* differential */
 166 #define ADS_A2A1A0_temp0        (0 << 4)        /* non-differential */
 167 #define ADS_A2A1A0_vbatt        (2 << 4)        /* non-differential */
 168 #define ADS_A2A1A0_vaux         (6 << 4)        /* non-differential */
 169 #define ADS_A2A1A0_temp1        (7 << 4)        /* non-differential */
 170 #define ADS_8_BIT               (1 << 3)
 171 #define ADS_12_BIT              (0 << 3)
 172 #define ADS_SER                 (1 << 2)        /* non-differential */
 173 #define ADS_DFR                 (0 << 2)        /* differential */
 174 #define ADS_PD10_PDOWN          (0 << 0)        /* low power mode + penirq */
 175 #define ADS_PD10_ADC_ON         (1 << 0)        /* ADC on */
 176 #define ADS_PD10_REF_ON         (2 << 0)        /* vREF on + penirq */
 177 #define ADS_PD10_ALL_ON         (3 << 0)        /* ADC + vREF on */
 178
 179 #define MAX_12BIT       ((1<<12)-1)
 180
 181 /* leave ADC powered up (disables penirq) between differential samples */
 182 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
 183         | ADS_12_BIT | ADS_DFR | \
 184         (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
 185
 186 #define READ_Y(vref)    (READ_12BIT_DFR(y,  1, vref))
 187 #define READ_Z1(vref)   (READ_12BIT_DFR(z1, 1, vref))
 188 #define READ_Z2(vref)   (READ_12BIT_DFR(z2, 1, vref))
 189
 190 #define READ_X(vref)    (READ_12BIT_DFR(x,  1, vref))
 191 #define PWRDOWN         (READ_12BIT_DFR(y,  0, 0))      /* LAST */
 192
 193 /* single-ended samples need to first power up reference voltage;
 194  * we leave both ADC and VREF powered
 195  */
 196 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
 197         | ADS_12_BIT | ADS_SER)
 198
 199 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
 200 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 201
 202 /* Must be called with ts->lock held */
 203 static void ads7846_stop(struct ads7846 *ts)
 204 {
 205         if (!ts->disabled && !ts->suspended) {
 206                 /* Signal IRQ thread to stop polling and disable the handler. */
 207                 ts->stopped = true;
 208                 mb();
 209                 wake_up(&ts->wait);
 210                 disable_irq(ts->spi->irq);
 211         }
 212 }
 213
 214 /* Must be called with ts->lock held */
 215 static void ads7846_restart(struct ads7846 *ts)
 216 {
 217         if (!ts->disabled && !ts->suspended) {
 218                 /* Tell IRQ thread that it may poll the device. */
 219                 ts->stopped = false;
 220                 mb();
 221                 enable_irq(ts->spi->irq);
 222         }
 223 }
 224
 225 /* Must be called with ts->lock held */
 226 static void __ads7846_disable(struct ads7846 *ts)
 227 {
 228         ads7846_stop(ts);
 229         regulator_disable(ts->reg);
 230
 231         /*
 232          * We know the chip's in low power mode since we always
 233          * leave it that way after every request
 234          */
 235 }
 236
 237 /* Must be called with ts->lock held */
 238 static void __ads7846_enable(struct ads7846 *ts)
 239 {
 240         int error;
 241
 242         error = regulator_enable(ts->reg);
 243         if (error != 0)
 244                 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
 245
 246         ads7846_restart(ts);
 247 }
 248
 249 static void ads7846_disable(struct ads7846 *ts)
 250 {
 251         mutex_lock(&ts->lock);
 252
 253         if (!ts->disabled) {
 254
 255                 if  (!ts->suspended)
 256                         __ads7846_disable(ts);
 257
 258                 ts->disabled = true;
 259         }
 260
 261         mutex_unlock(&ts->lock);
 262 }
 263
 264 static void ads7846_enable(struct ads7846 *ts)
 265 {
 266         mutex_lock(&ts->lock);
 267
 268         if (ts->disabled) {
 269
 270                 ts->disabled = false;
 271
 272                 if (!ts->suspended)
 273                         __ads7846_enable(ts);
 274         }
 275
 276         mutex_unlock(&ts->lock);
 277 }
 278
 279 /*--------------------------------------------------------------------------*/
 280
 281 /*
 282  * Non-touchscreen sensors only use single-ended conversions.
 283  * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
 284  * ads7846 lets that pin be unconnected, to use internal vREF.
 285  */
 286
 287 struct ser_req {
 288         u8                      ref_on;
 289         u8                      command;
 290         u8                      ref_off;
 291         u16                     scratch;
 292         struct spi_message      msg;
 293         struct spi_transfer     xfer[6];
 294         /*
 295          * DMA (thus cache coherency maintenance) requires the
 296          * transfer buffers to live in their own cache lines.
 297          */
 298         __be16 sample ____cacheline_aligned;
 299 };
 300
 301 struct ads7845_ser_req {
 302         u8                      command[3];
 303         struct spi_message      msg;
 304         struct spi_transfer     xfer[2];
 305         /*
 306          * DMA (thus cache coherency maintenance) requires the
 307          * transfer buffers to live in their own cache lines.
 308          */
 309         u8 sample[3] ____cacheline_aligned;
 310 };
 311
 312 static int ads7846_read12_ser(struct device *dev, unsigned command)
 313 {
 314         struct spi_device *spi = to_spi_device(dev);
 315         struct ads7846 *ts = dev_get_drvdata(dev);
 316         struct ser_req *req;
 317         int status;
 318
 319         req = kzalloc(sizeof *req, GFP_KERNEL);
 320         if (!req)
 321                 return -ENOMEM;
 322
 323         spi_message_init(&req->msg);
 324
 325         /* maybe turn on internal vREF, and let it settle */
 326         if (ts->use_internal) {
 327                 req->ref_on = REF_ON;
 328                 req->xfer[0].tx_buf = &req->ref_on;
 329                 req->xfer[0].len = 1;
 330                 spi_message_add_tail(&req->xfer[0], &req->msg);
 331
 332                 req->xfer[1].rx_buf = &req->scratch;
 333                 req->xfer[1].len = 2;
 334
 335                 /* for 1uF, settle for 800 usec; no cap, 100 usec.  */
 336                 req->xfer[1].delay.value = ts->vref_delay_usecs;
 337                 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS;
 338                 spi_message_add_tail(&req->xfer[1], &req->msg);
 339
 340                 /* Enable reference voltage */
 341                 command |= ADS_PD10_REF_ON;
 342         }
 343
 344         /* Enable ADC in every case */
 345         command |= ADS_PD10_ADC_ON;
 346
 347         /* take sample */
 348         req->command = (u8) command;
 349         req->xfer[2].tx_buf = &req->command;
 350         req->xfer[2].len = 1;
 351         spi_message_add_tail(&req->xfer[2], &req->msg);
 352
 353         req->xfer[3].rx_buf = &req->sample;
 354         req->xfer[3].len = 2;
 355         spi_message_add_tail(&req->xfer[3], &req->msg);
 356
 357         /* REVISIT:  take a few more samples, and compare ... */
 358
 359         /* converter in low power mode & enable PENIRQ */
 360         req->ref_off = PWRDOWN;
 361         req->xfer[4].tx_buf = &req->ref_off;
 362         req->xfer[4].len = 1;
 363         spi_message_add_tail(&req->xfer[4], &req->msg);
 364
 365         req->xfer[5].rx_buf = &req->scratch;
 366         req->xfer[5].len = 2;
 367         CS_CHANGE(req->xfer[5]);
 368         spi_message_add_tail(&req->xfer[5], &req->msg);
 369
 370         mutex_lock(&ts->lock);
 371         ads7846_stop(ts);
 372         status = spi_sync(spi, &req->msg);
 373         ads7846_restart(ts);
 374         mutex_unlock(&ts->lock);
 375
 376         if (status == 0) {
 377                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
 378                 status = be16_to_cpu(req->sample);
 379                 status = status >> 3;
 380                 status &= 0x0fff;
 381         }
 382
 383         kfree(req);
 384         return status;
 385 }
 386
 387 static int ads7845_read12_ser(struct device *dev, unsigned command)
 388 {
 389         struct spi_device *spi = to_spi_device(dev);
 390         struct ads7846 *ts = dev_get_drvdata(dev);
 391         struct ads7845_ser_req *req;
 392         int status;
 393
 394         req = kzalloc(sizeof *req, GFP_KERNEL);
 395         if (!req)
 396                 return -ENOMEM;
 397
 398         spi_message_init(&req->msg);
 399
 400         req->command[0] = (u8) command;
 401         req->xfer[0].tx_buf = req->command;
 402         req->xfer[0].rx_buf = req->sample;
 403         req->xfer[0].len = 3;
 404         spi_message_add_tail(&req->xfer[0], &req->msg);
 405
 406         mutex_lock(&ts->lock);
 407         ads7846_stop(ts);
 408         status = spi_sync(spi, &req->msg);
 409         ads7846_restart(ts);
 410         mutex_unlock(&ts->lock);
 411
 412         if (status == 0) {
 413                 /* BE12 value, then padding */
 414                 status = be16_to_cpu(*((u16 *)&req->sample[1]));
 415                 status = status >> 3;
 416                 status &= 0x0fff;
 417         }
 418
 419         kfree(req);
 420         return status;
 421 }
 422
 423 #if IS_ENABLED(CONFIG_HWMON)
 424
 425 #define SHOW(name, var, adjust) static ssize_t \
 426 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 427 { \
 428         struct ads7846 *ts = dev_get_drvdata(dev); \
 429         ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
 430                         READ_12BIT_SER(var)); \
 431         if (v < 0) \
 432                 return v; \
 433         return sprintf(buf, "%u\n", adjust(ts, v)); \
 434 } \
 435 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 436
 437
 438 /* Sysfs conventions report temperatures in millidegrees Celsius.
 439  * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
 440  * accuracy scheme without calibration data.  For now we won't try either;
 441  * userspace sees raw sensor values, and must scale/calibrate appropriately.
 442  */
 443 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
 444 {
 445         return v;
 446 }
 447
 448 SHOW(temp0, temp0, null_adjust)         /* temp1_input */
 449 SHOW(temp1, temp1, null_adjust)         /* temp2_input */
 450
 451
 452 /* sysfs conventions report voltages in millivolts.  We can convert voltages
 453  * if we know vREF.  userspace may need to scale vAUX to match the board's
 454  * external resistors; we assume that vBATT only uses the internal ones.
 455  */
 456 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
 457 {
 458         unsigned retval = v;
 459
 460         /* external resistors may scale vAUX into 0..vREF */
 461         retval *= ts->vref_mv;
 462         retval = retval >> 12;
 463
 464         return retval;
 465 }
 466
 467 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
 468 {
 469         unsigned retval = vaux_adjust(ts, v);
 470
 471         /* ads7846 has a resistor ladder to scale this signal down */
 472         if (ts->model == 7846)
 473                 retval *= 4;
 474
 475         return retval;
 476 }
 477
 478 SHOW(in0_input, vaux, vaux_adjust)
 479 SHOW(in1_input, vbatt, vbatt_adjust)
 480
 481 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
 482                                   int index)
 483 {
 484         struct device *dev = container_of(kobj, struct device, kobj);
 485         struct ads7846 *ts = dev_get_drvdata(dev);
 486
 487         if (ts->model == 7843 && index < 2)     /* in0, in1 */
 488                 return 0;
 489         if (ts->model == 7845 && index != 2)    /* in0 */
 490                 return 0;
 491
 492         return attr->mode;
 493 }
 494
 495 static struct attribute *ads7846_attributes[] = {
 496         &dev_attr_temp0.attr,           /* 0 */
 497         &dev_attr_temp1.attr,           /* 1 */
 498         &dev_attr_in0_input.attr,       /* 2 */
 499         &dev_attr_in1_input.attr,       /* 3 */
 500         NULL,
 501 };
 502
 503 static const struct attribute_group ads7846_attr_group = {
 504         .attrs = ads7846_attributes,
 505         .is_visible = ads7846_is_visible,
 506 };
 507 __ATTRIBUTE_GROUPS(ads7846_attr);
 508
 509 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 510 {
 511         /* hwmon sensors need a reference voltage */
 512         switch (ts->model) {
 513         case 7846:
 514                 if (!ts->vref_mv) {
 515                         dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
 516                         ts->vref_mv = 2500;
 517                         ts->use_internal = true;
 518                 }
 519                 break;
 520         case 7845:
 521         case 7843:
 522                 if (!ts->vref_mv) {
 523                         dev_warn(&spi->dev,
 524                                 "external vREF for ADS%d not specified\n",
 525                                 ts->model);
 526                         return 0;
 527                 }
 528                 break;
 529         }
 530
 531         ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
 532                                                       ts, ads7846_attr_groups);
 533
 534         return PTR_ERR_OR_ZERO(ts->hwmon);
 535 }
 536
 537 static void ads784x_hwmon_unregister(struct spi_device *spi,
 538                                      struct ads7846 *ts)
 539 {
 540         if (ts->hwmon)
 541                 hwmon_device_unregister(ts->hwmon);
 542 }
 543
 544 #else
 545 static inline int ads784x_hwmon_register(struct spi_device *spi,
 546                                          struct ads7846 *ts)
 547 {
 548         return 0;
 549 }
 550
 551 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
 552                                             struct ads7846 *ts)
 553 {
 554 }
 555 #endif
 556
 557 static ssize_t ads7846_pen_down_show(struct device *dev,
 558                                      struct device_attribute *attr, char *buf)
 559 {
 560         struct ads7846 *ts = dev_get_drvdata(dev);
 561
 562         return sprintf(buf, "%u\n", ts->pendown);
 563 }
 564
 565 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
 566
 567 static ssize_t ads7846_disable_show(struct device *dev,
 568                                      struct device_attribute *attr, char *buf)
 569 {
 570         struct ads7846 *ts = dev_get_drvdata(dev);
 571
 572         return sprintf(buf, "%u\n", ts->disabled);
 573 }
 574
 575 static ssize_t ads7846_disable_store(struct device *dev,
 576                                      struct device_attribute *attr,
 577                                      const char *buf, size_t count)
 578 {
 579         struct ads7846 *ts = dev_get_drvdata(dev);
 580         unsigned int i;
 581         int err;
 582
 583         err = kstrtouint(buf, 10, &i);
 584         if (err)
 585                 return err;
 586
 587         if (i)
 588                 ads7846_disable(ts);
 589         else
 590                 ads7846_enable(ts);
 591
 592         return count;
 593 }
 594
 595 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 596
 597 static struct attribute *ads784x_attributes[] = {
 598         &dev_attr_pen_down.attr,
 599         &dev_attr_disable.attr,
 600         NULL,
 601 };
 602
 603 static const struct attribute_group ads784x_attr_group = {
 604         .attrs = ads784x_attributes,
 605 };
 606
 607 /*--------------------------------------------------------------------------*/
 608
 609 static int get_pendown_state(struct ads7846 *ts)
 610 {
 611         if (ts->get_pendown_state)
 612                 return ts->get_pendown_state();
 613
 614         return !gpio_get_value(ts->gpio_pendown);
 615 }
 616
 617 static void null_wait_for_sync(void)
 618 {
 619 }
 620
 621 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
 622 {
 623         struct ads7846 *ts = ads;
 624
 625         if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 626                 /* Start over collecting consistent readings. */
 627                 ts->read_rep = 0;
 628                 /*
 629                  * Repeat it, if this was the first read or the read
 630                  * wasn't consistent enough.
 631                  */
 632                 if (ts->read_cnt < ts->debounce_max) {
 633                         ts->last_read = *val;
 634                         ts->read_cnt++;
 635                         return ADS7846_FILTER_REPEAT;
 636                 } else {
 637                         /*
 638                          * Maximum number of debouncing reached and still
 639                          * not enough number of consistent readings. Abort
 640                          * the whole sample, repeat it in the next sampling
 641                          * period.
 642                          */
 643                         ts->read_cnt = 0;
 644                         return ADS7846_FILTER_IGNORE;
 645                 }
 646         } else {
 647                 if (++ts->read_rep > ts->debounce_rep) {
 648                         /*
 649                          * Got a good reading for this coordinate,
 650                          * go for the next one.
 651                          */
 652                         ts->read_cnt = 0;
 653                         ts->read_rep = 0;
 654                         return ADS7846_FILTER_OK;
 655                 } else {
 656                         /* Read more values that are consistent. */
 657                         ts->read_cnt++;
 658                         return ADS7846_FILTER_REPEAT;
 659                 }
 660         }
 661 }
 662
 663 static int ads7846_no_filter(void *ads, int data_idx, int *val)
 664 {
 665         return ADS7846_FILTER_OK;
 666 }
 667
 668 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
 669 {
 670         int value;
 671         struct spi_transfer *t =
 672                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 673
 674         if (ts->model == 7845) {
 675                 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
 676         } else {
 677                 /*
 678                  * adjust:  on-wire is a must-ignore bit, a BE12 value, then
 679                  * padding; built from two 8 bit values written msb-first.
 680                  */
 681                 value = be16_to_cpup((__be16 *)t->rx_buf);
 682         }
 683
 684         /* enforce ADC output is 12 bits width */
 685         return (value >> 3) & 0xfff;
 686 }
 687
 688 static void ads7846_update_value(struct spi_message *m, int val)
 689 {
 690         struct spi_transfer *t =
 691                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 692
 693         *(u16 *)t->rx_buf = val;
 694 }
 695
 696 static void ads7846_read_state(struct ads7846 *ts)
 697 {
 698         struct ads7846_packet *packet = ts->packet;
 699         struct spi_message *m;
 700         int msg_idx = 0;
 701         int val;
 702         int action;
 703         int error;
 704
 705         while (msg_idx < ts->msg_count) {
 706
 707                 ts->wait_for_sync();
 708
 709                 m = &ts->msg[msg_idx];
 710                 error = spi_sync(ts->spi, m);
 711                 if (error) {
 712                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 713                         packet->tc.ignore = true;
 714                         return;
 715                 }
 716
 717                 /*
 718                  * Last message is power down request, no need to convert
 719                  * or filter the value.
 720                  */
 721                 if (msg_idx < ts->msg_count - 1) {
 722
 723                         val = ads7846_get_value(ts, m);
 724
 725                         action = ts->filter(ts->filter_data, msg_idx, &val);
 726                         switch (action) {
 727                         case ADS7846_FILTER_REPEAT:
 728                                 continue;
 729
 730                         case ADS7846_FILTER_IGNORE:
 731                                 packet->tc.ignore = true;
 732                                 msg_idx = ts->msg_count - 1;
 733                                 continue;
 734
 735                         case ADS7846_FILTER_OK:
 736                                 ads7846_update_value(m, val);
 737                                 packet->tc.ignore = false;
 738                                 msg_idx++;
 739                                 break;
 740
 741                         default:
 742                                 BUG();
 743                         }
 744                 } else {
 745                         msg_idx++;
 746                 }
 747         }
 748 }
 749
 750 static void ads7846_report_state(struct ads7846 *ts)
 751 {
 752         struct ads7846_packet *packet = ts->packet;
 753         unsigned int Rt;
 754         u16 x, y, z1, z2;
 755
 756         /*
 757          * ads7846_get_value() does in-place conversion (including byte swap)
 758          * from on-the-wire format as part of debouncing to get stable
 759          * readings.
 760          */
 761         if (ts->model == 7845) {
 762                 x = *(u16 *)packet->tc.x_buf;
 763                 y = *(u16 *)packet->tc.y_buf;
 764                 z1 = 0;
 765                 z2 = 0;
 766         } else {
 767                 x = packet->tc.x;
 768                 y = packet->tc.y;
 769                 z1 = packet->tc.z1;
 770                 z2 = packet->tc.z2;
 771         }
 772
 773         /* range filtering */
 774         if (x == MAX_12BIT)
 775                 x = 0;
 776
 777         if (ts->model == 7843) {
 778                 Rt = ts->pressure_max / 2;
 779         } else if (ts->model == 7845) {
 780                 if (get_pendown_state(ts))
 781                         Rt = ts->pressure_max / 2;
 782                 else
 783                         Rt = 0;
 784                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 785         } else if (likely(x && z1)) {
 786                 /* compute touch pressure resistance using equation #2 */
 787                 Rt = z2;
 788                 Rt -= z1;
 789                 Rt *= x;
 790                 Rt *= ts->x_plate_ohms;
 791                 Rt /= z1;
 792                 Rt = (Rt + 2047) >> 12;
 793         } else {
 794                 Rt = 0;
 795         }
 796
 797         /*
 798          * Sample found inconsistent by debouncing or pressure is beyond
 799          * the maximum. Don't report it to user space, repeat at least
 800          * once more the measurement
 801          */
 802         if (packet->tc.ignore || Rt > ts->pressure_max) {
 803                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 804                          packet->tc.ignore, Rt);
 805                 return;
 806         }
 807
 808         /*
 809          * Maybe check the pendown state before reporting. This discards
 810          * false readings when the pen is lifted.
 811          */
 812         if (ts->penirq_recheck_delay_usecs) {
 813                 udelay(ts->penirq_recheck_delay_usecs);
 814                 if (!get_pendown_state(ts))
 815                         Rt = 0;
 816         }
 817
 818         /*
 819          * NOTE: We can't rely on the pressure to determine the pen down
 820          * state, even this controller has a pressure sensor. The pressure
 821          * value can fluctuate for quite a while after lifting the pen and
 822          * in some cases may not even settle at the expected value.
 823          *
 824          * The only safe way to check for the pen up condition is in the
 825          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 826          */
 827         if (Rt) {
 828                 struct input_dev *input = ts->input;
 829
 830                 if (!ts->pendown) {
 831                         input_report_key(input, BTN_TOUCH, 1);
 832                         ts->pendown = true;
 833                         dev_vdbg(&ts->spi->dev, "DOWN\n");
 834                 }
 835
 836                 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
 837                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 838
 839                 input_sync(input);
 840                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
 841         }
 842 }
 843
 844 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 845 {
 846         struct ads7846 *ts = handle;
 847
 848         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 849 }
 850
 851
 852 static irqreturn_t ads7846_irq(int irq, void *handle)
 853 {
 854         struct ads7846 *ts = handle;
 855
 856         /* Start with a small delay before checking pendown state */
 857         msleep(TS_POLL_DELAY);
 858
 859         while (!ts->stopped && get_pendown_state(ts)) {
 860
 861                 /* pen is down, continue with the measurement */
 862                 ads7846_read_state(ts);
 863
 864                 if (!ts->stopped)
 865                         ads7846_report_state(ts);
 866
 867                 wait_event_timeout(ts->wait, ts->stopped,
 868                                    msecs_to_jiffies(TS_POLL_PERIOD));
 869         }
 870
 871         if (ts->pendown && !ts->stopped) {
 872                 struct input_dev *input = ts->input;
 873
 874                 input_report_key(input, BTN_TOUCH, 0);
 875                 input_report_abs(input, ABS_PRESSURE, 0);
 876                 input_sync(input);
 877
 878                 ts->pendown = false;
 879                 dev_vdbg(&ts->spi->dev, "UP\n");
 880         }
 881
 882         return IRQ_HANDLED;
 883 }
 884
 885 static int __maybe_unused ads7846_suspend(struct device *dev)
 886 {
 887         struct ads7846 *ts = dev_get_drvdata(dev);
 888
 889         mutex_lock(&ts->lock);
 890
 891         if (!ts->suspended) {
 892
 893                 if (!ts->disabled)
 894                         __ads7846_disable(ts);
 895
 896                 if (device_may_wakeup(&ts->spi->dev))
 897                         enable_irq_wake(ts->spi->irq);
 898
 899                 ts->suspended = true;
 900         }
 901
 902         mutex_unlock(&ts->lock);
 903
 904         return 0;
 905 }
 906
 907 static int __maybe_unused ads7846_resume(struct device *dev)
 908 {
 909         struct ads7846 *ts = dev_get_drvdata(dev);
 910
 911         mutex_lock(&ts->lock);
 912
 913         if (ts->suspended) {
 914
 915                 ts->suspended = false;
 916
 917                 if (device_may_wakeup(&ts->spi->dev))
 918                         disable_irq_wake(ts->spi->irq);
 919
 920                 if (!ts->disabled)
 921                         __ads7846_enable(ts);
 922         }
 923
 924         mutex_unlock(&ts->lock);
 925
 926         return 0;
 927 }
 928
 929 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 930
 931 static int ads7846_setup_pendown(struct spi_device *spi,
 932                                  struct ads7846 *ts,
 933                                  const struct ads7846_platform_data *pdata)
 934 {
 935         int err;
 936
 937         /*
 938          * REVISIT when the irq can be triggered active-low, or if for some
 939          * reason the touchscreen isn't hooked up, we don't need to access
 940          * the pendown state.
 941          */
 942
 943         if (pdata->get_pendown_state) {
 944                 ts->get_pendown_state = pdata->get_pendown_state;
 945         } else if (gpio_is_valid(pdata->gpio_pendown)) {
 946
 947                 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
 948                                        "ads7846_pendown");
 949                 if (err) {
 950                         dev_err(&spi->dev,
 951                                 "failed to request/setup pendown GPIO%d: %d\n",
 952                                 pdata->gpio_pendown, err);
 953                         return err;
 954                 }
 955
 956                 ts->gpio_pendown = pdata->gpio_pendown;
 957
 958                 if (pdata->gpio_pendown_debounce)
 959                         gpio_set_debounce(pdata->gpio_pendown,
 960                                           pdata->gpio_pendown_debounce);
 961         } else {
 962                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 963                 return -EINVAL;
 964         }
 965
 966         return 0;
 967 }
 968
 969 /*
 970  * Set up the transfers to read touchscreen state; this assumes we
 971  * use formula #2 for pressure, not #3.
 972  */
 973 static void ads7846_setup_spi_msg(struct ads7846 *ts,
 974                                   const struct ads7846_platform_data *pdata)
 975 {
 976         struct spi_message *m = &ts->msg[0];
 977         struct spi_transfer *x = ts->xfer;
 978         struct ads7846_packet *packet = ts->packet;
 979         int vref = pdata->keep_vref_on;
 980
 981         if (ts->model == 7873) {
 982                 /*
 983                  * The AD7873 is almost identical to the ADS7846
 984                  * keep VREF off during differential/ratiometric
 985                  * conversion modes.
 986                  */
 987                 ts->model = 7846;
 988                 vref = 0;
 989         }
 990
 991         ts->msg_count = 1;
 992         spi_message_init(m);
 993         m->context = ts;
 994
 995         if (ts->model == 7845) {
 996                 packet->read_y_cmd[0] = READ_Y(vref);
 997                 packet->read_y_cmd[1] = 0;
 998                 packet->read_y_cmd[2] = 0;
 999                 x->tx_buf = &packet->read_y_cmd[0];
1000                 x->rx_buf = &packet->tc.y_buf[0];
1001                 x->len = 3;
1002                 spi_message_add_tail(x, m);
1003         } else {
1004                 /* y- still on; turn on only y+ (and ADC) */
1005                 packet->read_y = READ_Y(vref);
1006                 x->tx_buf = &packet->read_y;
1007                 x->len = 1;
1008                 spi_message_add_tail(x, m);
1009
1010                 x++;
1011                 x->rx_buf = &packet->tc.y;
1012                 x->len = 2;
1013                 spi_message_add_tail(x, m);
1014         }
1015
1016         /*
1017          * The first sample after switching drivers can be low quality;
1018          * optionally discard it, using a second one after the signals
1019          * have had enough time to stabilize.
1020          */
1021         if (pdata->settle_delay_usecs) {
1022                 x->delay.value = pdata->settle_delay_usecs;
1023                 x->delay.unit = SPI_DELAY_UNIT_USECS;
1024
1025                 x++;
1026                 x->tx_buf = &packet->read_y;
1027                 x->len = 1;
1028                 spi_message_add_tail(x, m);
1029
1030                 x++;
1031                 x->rx_buf = &packet->tc.y;
1032                 x->len = 2;
1033                 spi_message_add_tail(x, m);
1034         }
1035
1036         ts->msg_count++;
1037         m++;
1038         spi_message_init(m);
1039         m->context = ts;
1040
1041         if (ts->model == 7845) {
1042                 x++;
1043                 packet->read_x_cmd[0] = READ_X(vref);
1044                 packet->read_x_cmd[1] = 0;
1045                 packet->read_x_cmd[2] = 0;
1046                 x->tx_buf = &packet->read_x_cmd[0];
1047                 x->rx_buf = &packet->tc.x_buf[0];
1048                 x->len = 3;
1049                 spi_message_add_tail(x, m);
1050         } else {
1051                 /* turn y- off, x+ on, then leave in lowpower */
1052                 x++;
1053                 packet->read_x = READ_X(vref);
1054                 x->tx_buf = &packet->read_x;
1055                 x->len = 1;
1056                 spi_message_add_tail(x, m);
1057
1058                 x++;
1059                 x->rx_buf = &packet->tc.x;
1060                 x->len = 2;
1061                 spi_message_add_tail(x, m);
1062         }
1063
1064         /* ... maybe discard first sample ... */
1065         if (pdata->settle_delay_usecs) {
1066                 x->delay.value = pdata->settle_delay_usecs;
1067                 x->delay.unit = SPI_DELAY_UNIT_USECS;
1068
1069                 x++;
1070                 x->tx_buf = &packet->read_x;
1071                 x->len = 1;
1072                 spi_message_add_tail(x, m);
1073
1074                 x++;
1075                 x->rx_buf = &packet->tc.x;
1076                 x->len = 2;
1077                 spi_message_add_tail(x, m);
1078         }
1079
1080         /* turn y+ off, x- on; we'll use formula #2 */
1081         if (ts->model == 7846) {
1082                 ts->msg_count++;
1083                 m++;
1084                 spi_message_init(m);
1085                 m->context = ts;
1086
1087                 x++;
1088                 packet->read_z1 = READ_Z1(vref);
1089                 x->tx_buf = &packet->read_z1;
1090                 x->len = 1;
1091                 spi_message_add_tail(x, m);
1092
1093                 x++;
1094                 x->rx_buf = &packet->tc.z1;
1095                 x->len = 2;
1096                 spi_message_add_tail(x, m);
1097
1098                 /* ... maybe discard first sample ... */
1099                 if (pdata->settle_delay_usecs) {
1100                         x->delay.value = pdata->settle_delay_usecs;
1101                         x->delay.unit = SPI_DELAY_UNIT_USECS;
1102
1103                         x++;
1104                         x->tx_buf = &packet->read_z1;
1105                         x->len = 1;
1106                         spi_message_add_tail(x, m);
1107
1108                         x++;
1109                         x->rx_buf = &packet->tc.z1;
1110                         x->len = 2;
1111                         spi_message_add_tail(x, m);
1112                 }
1113
1114                 ts->msg_count++;
1115                 m++;
1116                 spi_message_init(m);
1117                 m->context = ts;
1118
1119                 x++;
1120                 packet->read_z2 = READ_Z2(vref);
1121                 x->tx_buf = &packet->read_z2;
1122                 x->len = 1;
1123                 spi_message_add_tail(x, m);
1124
1125                 x++;
1126                 x->rx_buf = &packet->tc.z2;
1127                 x->len = 2;
1128                 spi_message_add_tail(x, m);
1129
1130                 /* ... maybe discard first sample ... */
1131                 if (pdata->settle_delay_usecs) {
1132                         x->delay.value = pdata->settle_delay_usecs;
1133                         x->delay.unit = SPI_DELAY_UNIT_USECS;
1134
1135                         x++;
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         }
1146
1147         /* power down */
1148         ts->msg_count++;
1149         m++;
1150         spi_message_init(m);
1151         m->context = ts;
1152
1153         if (ts->model == 7845) {
1154                 x++;
1155                 packet->pwrdown_cmd[0] = PWRDOWN;
1156                 packet->pwrdown_cmd[1] = 0;
1157                 packet->pwrdown_cmd[2] = 0;
1158                 x->tx_buf = &packet->pwrdown_cmd[0];
1159                 x->len = 3;
1160         } else {
1161                 x++;
1162                 packet->pwrdown = PWRDOWN;
1163                 x->tx_buf = &packet->pwrdown;
1164                 x->len = 1;
1165                 spi_message_add_tail(x, m);
1166
1167                 x++;
1168                 x->rx_buf = &packet->dummy;
1169                 x->len = 2;
1170         }
1171
1172         CS_CHANGE(*x);
1173         spi_message_add_tail(x, m);
1174 }
1175
1176 #ifdef CONFIG_OF
1177 static const struct of_device_id ads7846_dt_ids[] = {
1178         { .compatible = "ti,tsc2046",   .data = (void *) 7846 },
1179         { .compatible = "ti,ads7843",   .data = (void *) 7843 },
1180         { .compatible = "ti,ads7845",   .data = (void *) 7845 },
1181         { .compatible = "ti,ads7846",   .data = (void *) 7846 },
1182         { .compatible = "ti,ads7873",   .data = (void *) 7873 },
1183         { }
1184 };
1185 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1186
1187 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1188 {
1189         struct ads7846_platform_data *pdata;
1190         struct device_node *node = dev->of_node;
1191         const struct of_device_id *match;
1192         u32 value;
1193
1194         if (!node) {
1195                 dev_err(dev, "Device does not have associated DT data\n");
1196                 return ERR_PTR(-EINVAL);
1197         }
1198
1199         match = of_match_device(ads7846_dt_ids, dev);
1200         if (!match) {
1201                 dev_err(dev, "Unknown device model\n");
1202                 return ERR_PTR(-EINVAL);
1203         }
1204
1205         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1206         if (!pdata)
1207                 return ERR_PTR(-ENOMEM);
1208
1209         pdata->model = (unsigned long)match->data;
1210
1211         of_property_read_u16(node, "ti,vref-delay-usecs",
1212                              &pdata->vref_delay_usecs);
1213         of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1214         pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1215
1216         pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1217
1218         of_property_read_u16(node, "ti,settle-delay-usec",
1219                              &pdata->settle_delay_usecs);
1220         of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1221                              &pdata->penirq_recheck_delay_usecs);
1222
1223         of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1224         of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1225
1226         of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1227         of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1228         of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1229         of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1230
1231         /*
1232          * touchscreen-max-pressure gets parsed during
1233          * touchscreen_parse_properties()
1234          */
1235         of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1236         if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1237                 pdata->pressure_min = (u16) value;
1238         of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1239
1240         of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1241         if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1242                 pdata->debounce_max = (u16) value;
1243         of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1244         of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1245
1246         of_property_read_u32(node, "ti,pendown-gpio-debounce",
1247                              &pdata->gpio_pendown_debounce);
1248
1249         pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1250                         of_property_read_bool(node, "linux,wakeup");
1251
1252         pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1253
1254         return pdata;
1255 }
1256 #else
1257 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1258 {
1259         dev_err(dev, "no platform data defined\n");
1260         return ERR_PTR(-EINVAL);
1261 }
1262 #endif
1263
1264 static int ads7846_probe(struct spi_device *spi)
1265 {
1266         const struct ads7846_platform_data *pdata;
1267         struct ads7846 *ts;
1268         struct ads7846_packet *packet;
1269         struct input_dev *input_dev;
1270         unsigned long irq_flags;
1271         int err;
1272
1273         if (!spi->irq) {
1274                 dev_dbg(&spi->dev, "no IRQ?\n");
1275                 return -EINVAL;
1276         }
1277
1278         /* don't exceed max specified sample rate */
1279         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1280                 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1281                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1282                 return -EINVAL;
1283         }
1284
1285         /*
1286          * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1287          * that even if the hardware can do that, the SPI controller driver
1288          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1289          */
1290         spi->bits_per_word = 8;
1291         spi->mode = SPI_MODE_0;
1292         err = spi_setup(spi);
1293         if (err < 0)
1294                 return err;
1295
1296         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1297         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1298         input_dev = input_allocate_device();
1299         if (!ts || !packet || !input_dev) {
1300                 err = -ENOMEM;
1301                 goto err_free_mem;
1302         }
1303
1304         spi_set_drvdata(spi, ts);
1305
1306         ts->packet = packet;
1307         ts->spi = spi;
1308         ts->input = input_dev;
1309
1310         mutex_init(&ts->lock);
1311         init_waitqueue_head(&ts->wait);
1312
1313         pdata = dev_get_platdata(&spi->dev);
1314         if (!pdata) {
1315                 pdata = ads7846_probe_dt(&spi->dev);
1316                 if (IS_ERR(pdata)) {
1317                         err = PTR_ERR(pdata);
1318                         goto err_free_mem;
1319                 }
1320         }
1321
1322         ts->model = pdata->model ? : 7846;
1323         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1324         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1325         ts->vref_mv = pdata->vref_mv;
1326
1327         if (pdata->filter != NULL) {
1328                 if (pdata->filter_init != NULL) {
1329                         err = pdata->filter_init(pdata, &ts->filter_data);
1330                         if (err < 0)
1331                                 goto err_free_mem;
1332                 }
1333                 ts->filter = pdata->filter;
1334                 ts->filter_cleanup = pdata->filter_cleanup;
1335         } else if (pdata->debounce_max) {
1336                 ts->debounce_max = pdata->debounce_max;
1337                 if (ts->debounce_max < 2)
1338                         ts->debounce_max = 2;
1339                 ts->debounce_tol = pdata->debounce_tol;
1340                 ts->debounce_rep = pdata->debounce_rep;
1341                 ts->filter = ads7846_debounce_filter;
1342                 ts->filter_data = ts;
1343         } else {
1344                 ts->filter = ads7846_no_filter;
1345         }
1346
1347         err = ads7846_setup_pendown(spi, ts, pdata);
1348         if (err)
1349                 goto err_cleanup_filter;
1350
1351         if (pdata->penirq_recheck_delay_usecs)
1352                 ts->penirq_recheck_delay_usecs =
1353                                 pdata->penirq_recheck_delay_usecs;
1354
1355         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1356
1357         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1358         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1359
1360         input_dev->name = ts->name;
1361         input_dev->phys = ts->phys;
1362         input_dev->dev.parent = &spi->dev;
1363
1364         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1365         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1366         input_set_abs_params(input_dev, ABS_X,
1367                         pdata->x_min ? : 0,
1368                         pdata->x_max ? : MAX_12BIT,
1369                         0, 0);
1370         input_set_abs_params(input_dev, ABS_Y,
1371                         pdata->y_min ? : 0,
1372                         pdata->y_max ? : MAX_12BIT,
1373                         0, 0);
1374         input_set_abs_params(input_dev, ABS_PRESSURE,
1375                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1376
1377         /*
1378          * Parse common framework properties. Must be done here to ensure the
1379          * correct behaviour in case of using the legacy vendor bindings. The
1380          * general binding value overrides the vendor specific one.
1381          */
1382         touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1383         ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1384
1385         /*
1386          * Check if legacy ti,swap-xy binding is used instead of
1387          * touchscreen-swapped-x-y
1388          */
1389         if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1390                 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1391                 ts->core_prop.swap_x_y = true;
1392         }
1393
1394         ads7846_setup_spi_msg(ts, pdata);
1395
1396         ts->reg = regulator_get(&spi->dev, "vcc");
1397         if (IS_ERR(ts->reg)) {
1398                 err = PTR_ERR(ts->reg);
1399                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1400                 goto err_free_gpio;
1401         }
1402
1403         err = regulator_enable(ts->reg);
1404         if (err) {
1405                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1406                 goto err_put_regulator;
1407         }
1408
1409         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1410         irq_flags |= IRQF_ONESHOT;
1411
1412         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1413                                    irq_flags, spi->dev.driver->name, ts);
1414         if (err && !pdata->irq_flags) {
1415                 dev_info(&spi->dev,
1416                         "trying pin change workaround on irq %d\n", spi->irq);
1417                 irq_flags |= IRQF_TRIGGER_RISING;
1418                 err = request_threaded_irq(spi->irq,
1419                                   ads7846_hard_irq, ads7846_irq,
1420                                   irq_flags, spi->dev.driver->name, ts);
1421         }
1422
1423         if (err) {
1424                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1425                 goto err_disable_regulator;
1426         }
1427
1428         err = ads784x_hwmon_register(spi, ts);
1429         if (err)
1430                 goto err_free_irq;
1431
1432         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1433
1434         /*
1435          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1436          * the touchscreen, in case it's not connected.
1437          */
1438         if (ts->model == 7845)
1439                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1440         else
1441                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1442
1443         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1444         if (err)
1445                 goto err_remove_hwmon;
1446
1447         err = input_register_device(input_dev);
1448         if (err)
1449                 goto err_remove_attr_group;
1450
1451         device_init_wakeup(&spi->dev, pdata->wakeup);
1452
1453         /*
1454          * If device does not carry platform data we must have allocated it
1455          * when parsing DT data.
1456          */
1457         if (!dev_get_platdata(&spi->dev))
1458                 devm_kfree(&spi->dev, (void *)pdata);
1459
1460         return 0;
1461
1462  err_remove_attr_group:
1463         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1464  err_remove_hwmon:
1465         ads784x_hwmon_unregister(spi, ts);
1466  err_free_irq:
1467         free_irq(spi->irq, ts);
1468  err_disable_regulator:
1469         regulator_disable(ts->reg);
1470  err_put_regulator:
1471         regulator_put(ts->reg);
1472  err_free_gpio:
1473         if (!ts->get_pendown_state)
1474                 gpio_free(ts->gpio_pendown);
1475  err_cleanup_filter:
1476         if (ts->filter_cleanup)
1477                 ts->filter_cleanup(ts->filter_data);
1478  err_free_mem:
1479         input_free_device(input_dev);
1480         kfree(packet);
1481         kfree(ts);
1482         return err;
1483 }
1484
1485 static int ads7846_remove(struct spi_device *spi)
1486 {
1487         struct ads7846 *ts = spi_get_drvdata(spi);
1488
1489         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1490
1491         ads7846_disable(ts);
1492         free_irq(ts->spi->irq, ts);
1493
1494         input_unregister_device(ts->input);
1495
1496         ads784x_hwmon_unregister(spi, ts);
1497
1498         regulator_put(ts->reg);
1499
1500         if (!ts->get_pendown_state) {
1501                 /*
1502                  * If we are not using specialized pendown method we must
1503                  * have been relying on gpio we set up ourselves.
1504                  */
1505                 gpio_free(ts->gpio_pendown);
1506         }
1507
1508         if (ts->filter_cleanup)
1509                 ts->filter_cleanup(ts->filter_data);
1510
1511         kfree(ts->packet);
1512         kfree(ts);
1513
1514         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1515
1516         return 0;
1517 }
1518
1519 static struct spi_driver ads7846_driver = {
1520         .driver = {
1521                 .name   = "ads7846",
1522                 .pm     = &ads7846_pm,
1523                 .of_match_table = of_match_ptr(ads7846_dt_ids),
1524         },
1525         .probe          = ads7846_probe,
1526         .remove         = ads7846_remove,
1527 };
1528
1529 module_spi_driver(ads7846_driver);
1530
1531 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1532 MODULE_LICENSE("GPL");
1533 MODULE_ALIAS("spi:ads7846");