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 #include <asm/unaligned.h>
  37
  38 /*
  39  * This code has been heavily tested on a Nokia 770, and lightly
  40  * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
  41  * TSC2046 is just newer ads7846 silicon.
  42  * Support for ads7843 tested on Atmel at91sam926x-EK.
  43  * Support for ads7845 has only been stubbed in.
  44  * Support for Analog Devices AD7873 and AD7843 tested.
  45  *
  46  * IRQ handling needs a workaround because of a shortcoming in handling
  47  * edge triggered IRQs on some platforms like the OMAP1/2. These
  48  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
  49  * have to maintain our own SW IRQ disabled status. This should be
  50  * removed as soon as the affected platform's IRQ handling is fixed.
  51  *
  52  * App note sbaa036 talks in more detail about accurate sampling...
  53  * that ought to help in situations like LCDs inducing noise (which
  54  * can also be helped by using synch signals) and more generally.
  55  * This driver tries to utilize the measures described in the app
  56  * note. The strength of filtering can be set in the board-* specific
  57  * files.
  58  */
  59
  60 #define TS_POLL_DELAY   1       /* ms delay before the first sample */
  61 #define TS_POLL_PERIOD  5       /* ms delay between samples */
  62
  63 /* this driver doesn't aim at the peak continuous sample rate */
  64 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
  65
  66 struct ts_event {
  67         /*
  68          * For portability, we can't read 12 bit values using SPI (which
  69          * would make the controller deliver them as native byte order u16
  70          * with msbs zeroed).  Instead, we read them as two 8-bit values,
  71          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
  72          */
  73         u16     x;
  74         u16     y;
  75         u16     z1, z2;
  76         bool    ignore;
  77         u8      x_buf[3];
  78         u8      y_buf[3];
  79 };
  80
  81 /*
  82  * We allocate this separately to avoid cache line sharing issues when
  83  * driver is used with DMA-based SPI controllers (like atmel_spi) on
  84  * systems where main memory is not DMA-coherent (most non-x86 boards).
  85  */
  86 struct ads7846_packet {
  87         u8                      read_x, read_y, read_z1, read_z2, pwrdown;
  88         u16                     dummy;          /* for the pwrdown read */
  89         struct ts_event         tc;
  90         /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
  91         u8                      read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
  92 };
  93
  94 struct ads7846 {
  95         struct input_dev        *input;
  96         char                    phys[32];
  97         char                    name[32];
  98
  99         struct spi_device       *spi;
 100         struct regulator        *reg;
 101
 102 #if IS_ENABLED(CONFIG_HWMON)
 103         struct device           *hwmon;
 104 #endif
 105
 106         u16                     model;
 107         u16                     vref_mv;
 108         u16                     vref_delay_usecs;
 109         u16                     x_plate_ohms;
 110         u16                     pressure_max;
 111
 112         bool                    swap_xy;
 113         bool                    use_internal;
 114
 115         struct ads7846_packet   *packet;
 116
 117         struct spi_transfer     xfer[18];
 118         struct spi_message      msg[5];
 119         int                     msg_count;
 120         wait_queue_head_t       wait;
 121
 122         bool                    pendown;
 123
 124         int                     read_cnt;
 125         int                     read_rep;
 126         int                     last_read;
 127
 128         u16                     debounce_max;
 129         u16                     debounce_tol;
 130         u16                     debounce_rep;
 131
 132         u16                     penirq_recheck_delay_usecs;
 133
 134         struct touchscreen_properties core_prop;
 135
 136         struct mutex            lock;
 137         bool                    stopped;        /* P: lock */
 138         bool                    disabled;       /* P: lock */
 139         bool                    suspended;      /* P: lock */
 140
 141         int                     (*filter)(void *data, int data_idx, int *val);
 142         void                    *filter_data;
 143         void                    (*filter_cleanup)(void *data);
 144         int                     (*get_pendown_state)(void);
 145         int                     gpio_pendown;
 146
 147         void                    (*wait_for_sync)(void);
 148 };
 149
 150 /* leave chip selected when we're done, for quicker re-select? */
 151 #if     0
 152 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
 153 #else
 154 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
 155 #endif
 156
 157 /*--------------------------------------------------------------------------*/
 158
 159 /* The ADS7846 has touchscreen and other sensors.
 160  * Earlier ads784x chips are somewhat compatible.
 161  */
 162 #define ADS_START               (1 << 7)
 163 #define ADS_A2A1A0_d_y          (1 << 4)        /* differential */
 164 #define ADS_A2A1A0_d_z1         (3 << 4)        /* differential */
 165 #define ADS_A2A1A0_d_z2         (4 << 4)        /* differential */
 166 #define ADS_A2A1A0_d_x          (5 << 4)        /* differential */
 167 #define ADS_A2A1A0_temp0        (0 << 4)        /* non-differential */
 168 #define ADS_A2A1A0_vbatt        (2 << 4)        /* non-differential */
 169 #define ADS_A2A1A0_vaux         (6 << 4)        /* non-differential */
 170 #define ADS_A2A1A0_temp1        (7 << 4)        /* non-differential */
 171 #define ADS_8_BIT               (1 << 3)
 172 #define ADS_12_BIT              (0 << 3)
 173 #define ADS_SER                 (1 << 2)        /* non-differential */
 174 #define ADS_DFR                 (0 << 2)        /* differential */
 175 #define ADS_PD10_PDOWN          (0 << 0)        /* low power mode + penirq */
 176 #define ADS_PD10_ADC_ON         (1 << 0)        /* ADC on */
 177 #define ADS_PD10_REF_ON         (2 << 0)        /* vREF on + penirq */
 178 #define ADS_PD10_ALL_ON         (3 << 0)        /* ADC + vREF on */
 179
 180 #define MAX_12BIT       ((1<<12)-1)
 181
 182 /* leave ADC powered up (disables penirq) between differential samples */
 183 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
 184         | ADS_12_BIT | ADS_DFR | \
 185         (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
 186
 187 #define READ_Y(vref)    (READ_12BIT_DFR(y,  1, vref))
 188 #define READ_Z1(vref)   (READ_12BIT_DFR(z1, 1, vref))
 189 #define READ_Z2(vref)   (READ_12BIT_DFR(z2, 1, vref))
 190
 191 #define READ_X(vref)    (READ_12BIT_DFR(x,  1, vref))
 192 #define PWRDOWN         (READ_12BIT_DFR(y,  0, 0))      /* LAST */
 193
 194 /* single-ended samples need to first power up reference voltage;
 195  * we leave both ADC and VREF powered
 196  */
 197 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
 198         | ADS_12_BIT | ADS_SER)
 199
 200 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
 201 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 202
 203 static int get_pendown_state(struct ads7846 *ts)
 204 {
 205         if (ts->get_pendown_state)
 206                 return ts->get_pendown_state();
 207
 208         return !gpio_get_value(ts->gpio_pendown);
 209 }
 210
 211 static void ads7846_report_pen_up(struct ads7846 *ts)
 212 {
 213         struct input_dev *input = ts->input;
 214
 215         input_report_key(input, BTN_TOUCH, 0);
 216         input_report_abs(input, ABS_PRESSURE, 0);
 217         input_sync(input);
 218
 219         ts->pendown = false;
 220         dev_vdbg(&ts->spi->dev, "UP\n");
 221 }
 222
 223 /* Must be called with ts->lock held */
 224 static void ads7846_stop(struct ads7846 *ts)
 225 {
 226         if (!ts->disabled && !ts->suspended) {
 227                 /* Signal IRQ thread to stop polling and disable the handler. */
 228                 ts->stopped = true;
 229                 mb();
 230                 wake_up(&ts->wait);
 231                 disable_irq(ts->spi->irq);
 232         }
 233 }
 234
 235 /* Must be called with ts->lock held */
 236 static void ads7846_restart(struct ads7846 *ts)
 237 {
 238         if (!ts->disabled && !ts->suspended) {
 239                 /* Check if pen was released since last stop */
 240                 if (ts->pendown && !get_pendown_state(ts))
 241                         ads7846_report_pen_up(ts);
 242
 243                 /* Tell IRQ thread that it may poll the device. */
 244                 ts->stopped = false;
 245                 mb();
 246                 enable_irq(ts->spi->irq);
 247         }
 248 }
 249
 250 /* Must be called with ts->lock held */
 251 static void __ads7846_disable(struct ads7846 *ts)
 252 {
 253         ads7846_stop(ts);
 254         regulator_disable(ts->reg);
 255
 256         /*
 257          * We know the chip's in low power mode since we always
 258          * leave it that way after every request
 259          */
 260 }
 261
 262 /* Must be called with ts->lock held */
 263 static void __ads7846_enable(struct ads7846 *ts)
 264 {
 265         int error;
 266
 267         error = regulator_enable(ts->reg);
 268         if (error != 0)
 269                 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
 270
 271         ads7846_restart(ts);
 272 }
 273
 274 static void ads7846_disable(struct ads7846 *ts)
 275 {
 276         mutex_lock(&ts->lock);
 277
 278         if (!ts->disabled) {
 279
 280                 if  (!ts->suspended)
 281                         __ads7846_disable(ts);
 282
 283                 ts->disabled = true;
 284         }
 285
 286         mutex_unlock(&ts->lock);
 287 }
 288
 289 static void ads7846_enable(struct ads7846 *ts)
 290 {
 291         mutex_lock(&ts->lock);
 292
 293         if (ts->disabled) {
 294
 295                 ts->disabled = false;
 296
 297                 if (!ts->suspended)
 298                         __ads7846_enable(ts);
 299         }
 300
 301         mutex_unlock(&ts->lock);
 302 }
 303
 304 /*--------------------------------------------------------------------------*/
 305
 306 /*
 307  * Non-touchscreen sensors only use single-ended conversions.
 308  * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
 309  * ads7846 lets that pin be unconnected, to use internal vREF.
 310  */
 311
 312 struct ser_req {
 313         u8                      ref_on;
 314         u8                      command;
 315         u8                      ref_off;
 316         u16                     scratch;
 317         struct spi_message      msg;
 318         struct spi_transfer     xfer[6];
 319         /*
 320          * DMA (thus cache coherency maintenance) requires the
 321          * transfer buffers to live in their own cache lines.
 322          */
 323         __be16 sample ____cacheline_aligned;
 324 };
 325
 326 struct ads7845_ser_req {
 327         u8                      command[3];
 328         struct spi_message      msg;
 329         struct spi_transfer     xfer[2];
 330         /*
 331          * DMA (thus cache coherency maintenance) requires the
 332          * transfer buffers to live in their own cache lines.
 333          */
 334         u8 sample[3] ____cacheline_aligned;
 335 };
 336
 337 static int ads7846_read12_ser(struct device *dev, unsigned command)
 338 {
 339         struct spi_device *spi = to_spi_device(dev);
 340         struct ads7846 *ts = dev_get_drvdata(dev);
 341         struct ser_req *req;
 342         int status;
 343
 344         req = kzalloc(sizeof *req, GFP_KERNEL);
 345         if (!req)
 346                 return -ENOMEM;
 347
 348         spi_message_init(&req->msg);
 349
 350         /* maybe turn on internal vREF, and let it settle */
 351         if (ts->use_internal) {
 352                 req->ref_on = REF_ON;
 353                 req->xfer[0].tx_buf = &req->ref_on;
 354                 req->xfer[0].len = 1;
 355                 spi_message_add_tail(&req->xfer[0], &req->msg);
 356
 357                 req->xfer[1].rx_buf = &req->scratch;
 358                 req->xfer[1].len = 2;
 359
 360                 /* for 1uF, settle for 800 usec; no cap, 100 usec.  */
 361                 req->xfer[1].delay.value = ts->vref_delay_usecs;
 362                 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS;
 363                 spi_message_add_tail(&req->xfer[1], &req->msg);
 364
 365                 /* Enable reference voltage */
 366                 command |= ADS_PD10_REF_ON;
 367         }
 368
 369         /* Enable ADC in every case */
 370         command |= ADS_PD10_ADC_ON;
 371
 372         /* take sample */
 373         req->command = (u8) command;
 374         req->xfer[2].tx_buf = &req->command;
 375         req->xfer[2].len = 1;
 376         spi_message_add_tail(&req->xfer[2], &req->msg);
 377
 378         req->xfer[3].rx_buf = &req->sample;
 379         req->xfer[3].len = 2;
 380         spi_message_add_tail(&req->xfer[3], &req->msg);
 381
 382         /* REVISIT:  take a few more samples, and compare ... */
 383
 384         /* converter in low power mode & enable PENIRQ */
 385         req->ref_off = PWRDOWN;
 386         req->xfer[4].tx_buf = &req->ref_off;
 387         req->xfer[4].len = 1;
 388         spi_message_add_tail(&req->xfer[4], &req->msg);
 389
 390         req->xfer[5].rx_buf = &req->scratch;
 391         req->xfer[5].len = 2;
 392         CS_CHANGE(req->xfer[5]);
 393         spi_message_add_tail(&req->xfer[5], &req->msg);
 394
 395         mutex_lock(&ts->lock);
 396         ads7846_stop(ts);
 397         status = spi_sync(spi, &req->msg);
 398         ads7846_restart(ts);
 399         mutex_unlock(&ts->lock);
 400
 401         if (status == 0) {
 402                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
 403                 status = be16_to_cpu(req->sample);
 404                 status = status >> 3;
 405                 status &= 0x0fff;
 406         }
 407
 408         kfree(req);
 409         return status;
 410 }
 411
 412 static int ads7845_read12_ser(struct device *dev, unsigned command)
 413 {
 414         struct spi_device *spi = to_spi_device(dev);
 415         struct ads7846 *ts = dev_get_drvdata(dev);
 416         struct ads7845_ser_req *req;
 417         int status;
 418
 419         req = kzalloc(sizeof *req, GFP_KERNEL);
 420         if (!req)
 421                 return -ENOMEM;
 422
 423         spi_message_init(&req->msg);
 424
 425         req->command[0] = (u8) command;
 426         req->xfer[0].tx_buf = req->command;
 427         req->xfer[0].rx_buf = req->sample;
 428         req->xfer[0].len = 3;
 429         spi_message_add_tail(&req->xfer[0], &req->msg);
 430
 431         mutex_lock(&ts->lock);
 432         ads7846_stop(ts);
 433         status = spi_sync(spi, &req->msg);
 434         ads7846_restart(ts);
 435         mutex_unlock(&ts->lock);
 436
 437         if (status == 0) {
 438                 /* BE12 value, then padding */
 439                 status = get_unaligned_be16(&req->sample[1]);
 440                 status = status >> 3;
 441                 status &= 0x0fff;
 442         }
 443
 444         kfree(req);
 445         return status;
 446 }
 447
 448 #if IS_ENABLED(CONFIG_HWMON)
 449
 450 #define SHOW(name, var, adjust) static ssize_t \
 451 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 452 { \
 453         struct ads7846 *ts = dev_get_drvdata(dev); \
 454         ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
 455                         READ_12BIT_SER(var)); \
 456         if (v < 0) \
 457                 return v; \
 458         return sprintf(buf, "%u\n", adjust(ts, v)); \
 459 } \
 460 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 461
 462
 463 /* Sysfs conventions report temperatures in millidegrees Celsius.
 464  * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
 465  * accuracy scheme without calibration data.  For now we won't try either;
 466  * userspace sees raw sensor values, and must scale/calibrate appropriately.
 467  */
 468 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
 469 {
 470         return v;
 471 }
 472
 473 SHOW(temp0, temp0, null_adjust)         /* temp1_input */
 474 SHOW(temp1, temp1, null_adjust)         /* temp2_input */
 475
 476
 477 /* sysfs conventions report voltages in millivolts.  We can convert voltages
 478  * if we know vREF.  userspace may need to scale vAUX to match the board's
 479  * external resistors; we assume that vBATT only uses the internal ones.
 480  */
 481 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
 482 {
 483         unsigned retval = v;
 484
 485         /* external resistors may scale vAUX into 0..vREF */
 486         retval *= ts->vref_mv;
 487         retval = retval >> 12;
 488
 489         return retval;
 490 }
 491
 492 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
 493 {
 494         unsigned retval = vaux_adjust(ts, v);
 495
 496         /* ads7846 has a resistor ladder to scale this signal down */
 497         if (ts->model == 7846)
 498                 retval *= 4;
 499
 500         return retval;
 501 }
 502
 503 SHOW(in0_input, vaux, vaux_adjust)
 504 SHOW(in1_input, vbatt, vbatt_adjust)
 505
 506 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
 507                                   int index)
 508 {
 509         struct device *dev = container_of(kobj, struct device, kobj);
 510         struct ads7846 *ts = dev_get_drvdata(dev);
 511
 512         if (ts->model == 7843 && index < 2)     /* in0, in1 */
 513                 return 0;
 514         if (ts->model == 7845 && index != 2)    /* in0 */
 515                 return 0;
 516
 517         return attr->mode;
 518 }
 519
 520 static struct attribute *ads7846_attributes[] = {
 521         &dev_attr_temp0.attr,           /* 0 */
 522         &dev_attr_temp1.attr,           /* 1 */
 523         &dev_attr_in0_input.attr,       /* 2 */
 524         &dev_attr_in1_input.attr,       /* 3 */
 525         NULL,
 526 };
 527
 528 static const struct attribute_group ads7846_attr_group = {
 529         .attrs = ads7846_attributes,
 530         .is_visible = ads7846_is_visible,
 531 };
 532 __ATTRIBUTE_GROUPS(ads7846_attr);
 533
 534 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 535 {
 536         /* hwmon sensors need a reference voltage */
 537         switch (ts->model) {
 538         case 7846:
 539                 if (!ts->vref_mv) {
 540                         dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
 541                         ts->vref_mv = 2500;
 542                         ts->use_internal = true;
 543                 }
 544                 break;
 545         case 7845:
 546         case 7843:
 547                 if (!ts->vref_mv) {
 548                         dev_warn(&spi->dev,
 549                                 "external vREF for ADS%d not specified\n",
 550                                 ts->model);
 551                         return 0;
 552                 }
 553                 break;
 554         }
 555
 556         ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
 557                                                       ts, ads7846_attr_groups);
 558
 559         return PTR_ERR_OR_ZERO(ts->hwmon);
 560 }
 561
 562 static void ads784x_hwmon_unregister(struct spi_device *spi,
 563                                      struct ads7846 *ts)
 564 {
 565         if (ts->hwmon)
 566                 hwmon_device_unregister(ts->hwmon);
 567 }
 568
 569 #else
 570 static inline int ads784x_hwmon_register(struct spi_device *spi,
 571                                          struct ads7846 *ts)
 572 {
 573         return 0;
 574 }
 575
 576 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
 577                                             struct ads7846 *ts)
 578 {
 579 }
 580 #endif
 581
 582 static ssize_t ads7846_pen_down_show(struct device *dev,
 583                                      struct device_attribute *attr, char *buf)
 584 {
 585         struct ads7846 *ts = dev_get_drvdata(dev);
 586
 587         return sprintf(buf, "%u\n", ts->pendown);
 588 }
 589
 590 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
 591
 592 static ssize_t ads7846_disable_show(struct device *dev,
 593                                      struct device_attribute *attr, char *buf)
 594 {
 595         struct ads7846 *ts = dev_get_drvdata(dev);
 596
 597         return sprintf(buf, "%u\n", ts->disabled);
 598 }
 599
 600 static ssize_t ads7846_disable_store(struct device *dev,
 601                                      struct device_attribute *attr,
 602                                      const char *buf, size_t count)
 603 {
 604         struct ads7846 *ts = dev_get_drvdata(dev);
 605         unsigned int i;
 606         int err;
 607
 608         err = kstrtouint(buf, 10, &i);
 609         if (err)
 610                 return err;
 611
 612         if (i)
 613                 ads7846_disable(ts);
 614         else
 615                 ads7846_enable(ts);
 616
 617         return count;
 618 }
 619
 620 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 621
 622 static struct attribute *ads784x_attributes[] = {
 623         &dev_attr_pen_down.attr,
 624         &dev_attr_disable.attr,
 625         NULL,
 626 };
 627
 628 static const struct attribute_group ads784x_attr_group = {
 629         .attrs = ads784x_attributes,
 630 };
 631
 632 /*--------------------------------------------------------------------------*/
 633
 634 static void null_wait_for_sync(void)
 635 {
 636 }
 637
 638 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
 639 {
 640         struct ads7846 *ts = ads;
 641
 642         if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 643                 /* Start over collecting consistent readings. */
 644                 ts->read_rep = 0;
 645                 /*
 646                  * Repeat it, if this was the first read or the read
 647                  * wasn't consistent enough.
 648                  */
 649                 if (ts->read_cnt < ts->debounce_max) {
 650                         ts->last_read = *val;
 651                         ts->read_cnt++;
 652                         return ADS7846_FILTER_REPEAT;
 653                 } else {
 654                         /*
 655                          * Maximum number of debouncing reached and still
 656                          * not enough number of consistent readings. Abort
 657                          * the whole sample, repeat it in the next sampling
 658                          * period.
 659                          */
 660                         ts->read_cnt = 0;
 661                         return ADS7846_FILTER_IGNORE;
 662                 }
 663         } else {
 664                 if (++ts->read_rep > ts->debounce_rep) {
 665                         /*
 666                          * Got a good reading for this coordinate,
 667                          * go for the next one.
 668                          */
 669                         ts->read_cnt = 0;
 670                         ts->read_rep = 0;
 671                         return ADS7846_FILTER_OK;
 672                 } else {
 673                         /* Read more values that are consistent. */
 674                         ts->read_cnt++;
 675                         return ADS7846_FILTER_REPEAT;
 676                 }
 677         }
 678 }
 679
 680 static int ads7846_no_filter(void *ads, int data_idx, int *val)
 681 {
 682         return ADS7846_FILTER_OK;
 683 }
 684
 685 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
 686 {
 687         int value;
 688         struct spi_transfer *t =
 689                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 690
 691         if (ts->model == 7845) {
 692                 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
 693         } else {
 694                 /*
 695                  * adjust:  on-wire is a must-ignore bit, a BE12 value, then
 696                  * padding; built from two 8 bit values written msb-first.
 697                  */
 698                 value = be16_to_cpup((__be16 *)t->rx_buf);
 699         }
 700
 701         /* enforce ADC output is 12 bits width */
 702         return (value >> 3) & 0xfff;
 703 }
 704
 705 static void ads7846_update_value(struct spi_message *m, int val)
 706 {
 707         struct spi_transfer *t =
 708                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 709
 710         *(u16 *)t->rx_buf = val;
 711 }
 712
 713 static void ads7846_read_state(struct ads7846 *ts)
 714 {
 715         struct ads7846_packet *packet = ts->packet;
 716         struct spi_message *m;
 717         int msg_idx = 0;
 718         int val;
 719         int action;
 720         int error;
 721
 722         while (msg_idx < ts->msg_count) {
 723
 724                 ts->wait_for_sync();
 725
 726                 m = &ts->msg[msg_idx];
 727                 error = spi_sync(ts->spi, m);
 728                 if (error) {
 729                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 730                         packet->tc.ignore = true;
 731                         return;
 732                 }
 733
 734                 /*
 735                  * Last message is power down request, no need to convert
 736                  * or filter the value.
 737                  */
 738                 if (msg_idx < ts->msg_count - 1) {
 739
 740                         val = ads7846_get_value(ts, m);
 741
 742                         action = ts->filter(ts->filter_data, msg_idx, &val);
 743                         switch (action) {
 744                         case ADS7846_FILTER_REPEAT:
 745                                 continue;
 746
 747                         case ADS7846_FILTER_IGNORE:
 748                                 packet->tc.ignore = true;
 749                                 msg_idx = ts->msg_count - 1;
 750                                 continue;
 751
 752                         case ADS7846_FILTER_OK:
 753                                 ads7846_update_value(m, val);
 754                                 packet->tc.ignore = false;
 755                                 msg_idx++;
 756                                 break;
 757
 758                         default:
 759                                 BUG();
 760                         }
 761                 } else {
 762                         msg_idx++;
 763                 }
 764         }
 765 }
 766
 767 static void ads7846_report_state(struct ads7846 *ts)
 768 {
 769         struct ads7846_packet *packet = ts->packet;
 770         unsigned int Rt;
 771         u16 x, y, z1, z2;
 772
 773         /*
 774          * ads7846_get_value() does in-place conversion (including byte swap)
 775          * from on-the-wire format as part of debouncing to get stable
 776          * readings.
 777          */
 778         if (ts->model == 7845) {
 779                 x = *(u16 *)packet->tc.x_buf;
 780                 y = *(u16 *)packet->tc.y_buf;
 781                 z1 = 0;
 782                 z2 = 0;
 783         } else {
 784                 x = packet->tc.x;
 785                 y = packet->tc.y;
 786                 z1 = packet->tc.z1;
 787                 z2 = packet->tc.z2;
 788         }
 789
 790         /* range filtering */
 791         if (x == MAX_12BIT)
 792                 x = 0;
 793
 794         if (ts->model == 7843) {
 795                 Rt = ts->pressure_max / 2;
 796         } else if (ts->model == 7845) {
 797                 if (get_pendown_state(ts))
 798                         Rt = ts->pressure_max / 2;
 799                 else
 800                         Rt = 0;
 801                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 802         } else if (likely(x && z1)) {
 803                 /* compute touch pressure resistance using equation #2 */
 804                 Rt = z2;
 805                 Rt -= z1;
 806                 Rt *= ts->x_plate_ohms;
 807                 Rt = DIV_ROUND_CLOSEST(Rt, 16);
 808                 Rt *= x;
 809                 Rt /= z1;
 810                 Rt = DIV_ROUND_CLOSEST(Rt, 256);
 811         } else {
 812                 Rt = 0;
 813         }
 814
 815         /*
 816          * Sample found inconsistent by debouncing or pressure is beyond
 817          * the maximum. Don't report it to user space, repeat at least
 818          * once more the measurement
 819          */
 820         if (packet->tc.ignore || Rt > ts->pressure_max) {
 821                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 822                          packet->tc.ignore, Rt);
 823                 return;
 824         }
 825
 826         /*
 827          * Maybe check the pendown state before reporting. This discards
 828          * false readings when the pen is lifted.
 829          */
 830         if (ts->penirq_recheck_delay_usecs) {
 831                 udelay(ts->penirq_recheck_delay_usecs);
 832                 if (!get_pendown_state(ts))
 833                         Rt = 0;
 834         }
 835
 836         /*
 837          * NOTE: We can't rely on the pressure to determine the pen down
 838          * state, even this controller has a pressure sensor. The pressure
 839          * value can fluctuate for quite a while after lifting the pen and
 840          * in some cases may not even settle at the expected value.
 841          *
 842          * The only safe way to check for the pen up condition is in the
 843          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 844          */
 845         if (Rt) {
 846                 struct input_dev *input = ts->input;
 847
 848                 if (!ts->pendown) {
 849                         input_report_key(input, BTN_TOUCH, 1);
 850                         ts->pendown = true;
 851                         dev_vdbg(&ts->spi->dev, "DOWN\n");
 852                 }
 853
 854                 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
 855                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 856
 857                 input_sync(input);
 858                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
 859         }
 860 }
 861
 862 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 863 {
 864         struct ads7846 *ts = handle;
 865
 866         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 867 }
 868
 869
 870 static irqreturn_t ads7846_irq(int irq, void *handle)
 871 {
 872         struct ads7846 *ts = handle;
 873
 874         /* Start with a small delay before checking pendown state */
 875         msleep(TS_POLL_DELAY);
 876
 877         while (!ts->stopped && get_pendown_state(ts)) {
 878
 879                 /* pen is down, continue with the measurement */
 880                 ads7846_read_state(ts);
 881
 882                 if (!ts->stopped)
 883                         ads7846_report_state(ts);
 884
 885                 wait_event_timeout(ts->wait, ts->stopped,
 886                                    msecs_to_jiffies(TS_POLL_PERIOD));
 887         }
 888
 889         if (ts->pendown && !ts->stopped)
 890                 ads7846_report_pen_up(ts);
 891
 892         return IRQ_HANDLED;
 893 }
 894
 895 static int __maybe_unused ads7846_suspend(struct device *dev)
 896 {
 897         struct ads7846 *ts = dev_get_drvdata(dev);
 898
 899         mutex_lock(&ts->lock);
 900
 901         if (!ts->suspended) {
 902
 903                 if (!ts->disabled)
 904                         __ads7846_disable(ts);
 905
 906                 if (device_may_wakeup(&ts->spi->dev))
 907                         enable_irq_wake(ts->spi->irq);
 908
 909                 ts->suspended = true;
 910         }
 911
 912         mutex_unlock(&ts->lock);
 913
 914         return 0;
 915 }
 916
 917 static int __maybe_unused ads7846_resume(struct device *dev)
 918 {
 919         struct ads7846 *ts = dev_get_drvdata(dev);
 920
 921         mutex_lock(&ts->lock);
 922
 923         if (ts->suspended) {
 924
 925                 ts->suspended = false;
 926
 927                 if (device_may_wakeup(&ts->spi->dev))
 928                         disable_irq_wake(ts->spi->irq);
 929
 930                 if (!ts->disabled)
 931                         __ads7846_enable(ts);
 932         }
 933
 934         mutex_unlock(&ts->lock);
 935
 936         return 0;
 937 }
 938
 939 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 940
 941 static int ads7846_setup_pendown(struct spi_device *spi,
 942                                  struct ads7846 *ts,
 943                                  const struct ads7846_platform_data *pdata)
 944 {
 945         int err;
 946
 947         /*
 948          * REVISIT when the irq can be triggered active-low, or if for some
 949          * reason the touchscreen isn't hooked up, we don't need to access
 950          * the pendown state.
 951          */
 952
 953         if (pdata->get_pendown_state) {
 954                 ts->get_pendown_state = pdata->get_pendown_state;
 955         } else if (gpio_is_valid(pdata->gpio_pendown)) {
 956
 957                 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
 958                                        "ads7846_pendown");
 959                 if (err) {
 960                         dev_err(&spi->dev,
 961                                 "failed to request/setup pendown GPIO%d: %d\n",
 962                                 pdata->gpio_pendown, err);
 963                         return err;
 964                 }
 965
 966                 ts->gpio_pendown = pdata->gpio_pendown;
 967
 968                 if (pdata->gpio_pendown_debounce)
 969                         gpio_set_debounce(pdata->gpio_pendown,
 970                                           pdata->gpio_pendown_debounce);
 971         } else {
 972                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 973                 return -EINVAL;
 974         }
 975
 976         return 0;
 977 }
 978
 979 /*
 980  * Set up the transfers to read touchscreen state; this assumes we
 981  * use formula #2 for pressure, not #3.
 982  */
 983 static void ads7846_setup_spi_msg(struct ads7846 *ts,
 984                                   const struct ads7846_platform_data *pdata)
 985 {
 986         struct spi_message *m = &ts->msg[0];
 987         struct spi_transfer *x = ts->xfer;
 988         struct ads7846_packet *packet = ts->packet;
 989         int vref = pdata->keep_vref_on;
 990
 991         if (ts->model == 7873) {
 992                 /*
 993                  * The AD7873 is almost identical to the ADS7846
 994                  * keep VREF off during differential/ratiometric
 995                  * conversion modes.
 996                  */
 997                 ts->model = 7846;
 998                 vref = 0;
 999         }
1000
1001         ts->msg_count = 1;
1002         spi_message_init(m);
1003         m->context = ts;
1004
1005         if (ts->model == 7845) {
1006                 packet->read_y_cmd[0] = READ_Y(vref);
1007                 packet->read_y_cmd[1] = 0;
1008                 packet->read_y_cmd[2] = 0;
1009                 x->tx_buf = &packet->read_y_cmd[0];
1010                 x->rx_buf = &packet->tc.y_buf[0];
1011                 x->len = 3;
1012                 spi_message_add_tail(x, m);
1013         } else {
1014                 /* y- still on; turn on only y+ (and ADC) */
1015                 packet->read_y = READ_Y(vref);
1016                 x->tx_buf = &packet->read_y;
1017                 x->len = 1;
1018                 spi_message_add_tail(x, m);
1019
1020                 x++;
1021                 x->rx_buf = &packet->tc.y;
1022                 x->len = 2;
1023                 spi_message_add_tail(x, m);
1024         }
1025
1026         /*
1027          * The first sample after switching drivers can be low quality;
1028          * optionally discard it, using a second one after the signals
1029          * have had enough time to stabilize.
1030          */
1031         if (pdata->settle_delay_usecs) {
1032                 x->delay.value = pdata->settle_delay_usecs;
1033                 x->delay.unit = SPI_DELAY_UNIT_USECS;
1034
1035                 x++;
1036                 x->tx_buf = &packet->read_y;
1037                 x->len = 1;
1038                 spi_message_add_tail(x, m);
1039
1040                 x++;
1041                 x->rx_buf = &packet->tc.y;
1042                 x->len = 2;
1043                 spi_message_add_tail(x, m);
1044         }
1045
1046         ts->msg_count++;
1047         m++;
1048         spi_message_init(m);
1049         m->context = ts;
1050
1051         if (ts->model == 7845) {
1052                 x++;
1053                 packet->read_x_cmd[0] = READ_X(vref);
1054                 packet->read_x_cmd[1] = 0;
1055                 packet->read_x_cmd[2] = 0;
1056                 x->tx_buf = &packet->read_x_cmd[0];
1057                 x->rx_buf = &packet->tc.x_buf[0];
1058                 x->len = 3;
1059                 spi_message_add_tail(x, m);
1060         } else {
1061                 /* turn y- off, x+ on, then leave in lowpower */
1062                 x++;
1063                 packet->read_x = READ_X(vref);
1064                 x->tx_buf = &packet->read_x;
1065                 x->len = 1;
1066                 spi_message_add_tail(x, m);
1067
1068                 x++;
1069                 x->rx_buf = &packet->tc.x;
1070                 x->len = 2;
1071                 spi_message_add_tail(x, m);
1072         }
1073
1074         /* ... maybe discard first sample ... */
1075         if (pdata->settle_delay_usecs) {
1076                 x->delay.value = pdata->settle_delay_usecs;
1077                 x->delay.unit = SPI_DELAY_UNIT_USECS;
1078
1079                 x++;
1080                 x->tx_buf = &packet->read_x;
1081                 x->len = 1;
1082                 spi_message_add_tail(x, m);
1083
1084                 x++;
1085                 x->rx_buf = &packet->tc.x;
1086                 x->len = 2;
1087                 spi_message_add_tail(x, m);
1088         }
1089
1090         /* turn y+ off, x- on; we'll use formula #2 */
1091         if (ts->model == 7846) {
1092                 ts->msg_count++;
1093                 m++;
1094                 spi_message_init(m);
1095                 m->context = ts;
1096
1097                 x++;
1098                 packet->read_z1 = READ_Z1(vref);
1099                 x->tx_buf = &packet->read_z1;
1100                 x->len = 1;
1101                 spi_message_add_tail(x, m);
1102
1103                 x++;
1104                 x->rx_buf = &packet->tc.z1;
1105                 x->len = 2;
1106                 spi_message_add_tail(x, m);
1107
1108                 /* ... maybe discard first sample ... */
1109                 if (pdata->settle_delay_usecs) {
1110                         x->delay.value = pdata->settle_delay_usecs;
1111                         x->delay.unit = SPI_DELAY_UNIT_USECS;
1112
1113                         x++;
1114                         x->tx_buf = &packet->read_z1;
1115                         x->len = 1;
1116                         spi_message_add_tail(x, m);
1117
1118                         x++;
1119                         x->rx_buf = &packet->tc.z1;
1120                         x->len = 2;
1121                         spi_message_add_tail(x, m);
1122                 }
1123
1124                 ts->msg_count++;
1125                 m++;
1126                 spi_message_init(m);
1127                 m->context = ts;
1128
1129                 x++;
1130                 packet->read_z2 = READ_Z2(vref);
1131                 x->tx_buf = &packet->read_z2;
1132                 x->len = 1;
1133                 spi_message_add_tail(x, m);
1134
1135                 x++;
1136                 x->rx_buf = &packet->tc.z2;
1137                 x->len = 2;
1138                 spi_message_add_tail(x, m);
1139
1140                 /* ... maybe discard first sample ... */
1141                 if (pdata->settle_delay_usecs) {
1142                         x->delay.value = pdata->settle_delay_usecs;
1143                         x->delay.unit = SPI_DELAY_UNIT_USECS;
1144
1145                         x++;
1146                         x->tx_buf = &packet->read_z2;
1147                         x->len = 1;
1148                         spi_message_add_tail(x, m);
1149
1150                         x++;
1151                         x->rx_buf = &packet->tc.z2;
1152                         x->len = 2;
1153                         spi_message_add_tail(x, m);
1154                 }
1155         }
1156
1157         /* power down */
1158         ts->msg_count++;
1159         m++;
1160         spi_message_init(m);
1161         m->context = ts;
1162
1163         if (ts->model == 7845) {
1164                 x++;
1165                 packet->pwrdown_cmd[0] = PWRDOWN;
1166                 packet->pwrdown_cmd[1] = 0;
1167                 packet->pwrdown_cmd[2] = 0;
1168                 x->tx_buf = &packet->pwrdown_cmd[0];
1169                 x->len = 3;
1170         } else {
1171                 x++;
1172                 packet->pwrdown = PWRDOWN;
1173                 x->tx_buf = &packet->pwrdown;
1174                 x->len = 1;
1175                 spi_message_add_tail(x, m);
1176
1177                 x++;
1178                 x->rx_buf = &packet->dummy;
1179                 x->len = 2;
1180         }
1181
1182         CS_CHANGE(*x);
1183         spi_message_add_tail(x, m);
1184 }
1185
1186 #ifdef CONFIG_OF
1187 static const struct of_device_id ads7846_dt_ids[] = {
1188         { .compatible = "ti,tsc2046",   .data = (void *) 7846 },
1189         { .compatible = "ti,ads7843",   .data = (void *) 7843 },
1190         { .compatible = "ti,ads7845",   .data = (void *) 7845 },
1191         { .compatible = "ti,ads7846",   .data = (void *) 7846 },
1192         { .compatible = "ti,ads7873",   .data = (void *) 7873 },
1193         { }
1194 };
1195 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1196
1197 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1198 {
1199         struct ads7846_platform_data *pdata;
1200         struct device_node *node = dev->of_node;
1201         const struct of_device_id *match;
1202         u32 value;
1203
1204         if (!node) {
1205                 dev_err(dev, "Device does not have associated DT data\n");
1206                 return ERR_PTR(-EINVAL);
1207         }
1208
1209         match = of_match_device(ads7846_dt_ids, dev);
1210         if (!match) {
1211                 dev_err(dev, "Unknown device model\n");
1212                 return ERR_PTR(-EINVAL);
1213         }
1214
1215         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1216         if (!pdata)
1217                 return ERR_PTR(-ENOMEM);
1218
1219         pdata->model = (unsigned long)match->data;
1220
1221         of_property_read_u16(node, "ti,vref-delay-usecs",
1222                              &pdata->vref_delay_usecs);
1223         of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1224         pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1225
1226         pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1227
1228         of_property_read_u16(node, "ti,settle-delay-usec",
1229                              &pdata->settle_delay_usecs);
1230         of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1231                              &pdata->penirq_recheck_delay_usecs);
1232
1233         of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1234         of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1235
1236         of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1237         of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1238         of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1239         of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1240
1241         /*
1242          * touchscreen-max-pressure gets parsed during
1243          * touchscreen_parse_properties()
1244          */
1245         of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1246         if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1247                 pdata->pressure_min = (u16) value;
1248         of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1249
1250         of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1251         if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1252                 pdata->debounce_max = (u16) value;
1253         of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1254         of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1255
1256         of_property_read_u32(node, "ti,pendown-gpio-debounce",
1257                              &pdata->gpio_pendown_debounce);
1258
1259         pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1260                         of_property_read_bool(node, "linux,wakeup");
1261
1262         pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1263
1264         return pdata;
1265 }
1266 #else
1267 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1268 {
1269         dev_err(dev, "no platform data defined\n");
1270         return ERR_PTR(-EINVAL);
1271 }
1272 #endif
1273
1274 static int ads7846_probe(struct spi_device *spi)
1275 {
1276         const struct ads7846_platform_data *pdata;
1277         struct ads7846 *ts;
1278         struct ads7846_packet *packet;
1279         struct input_dev *input_dev;
1280         unsigned long irq_flags;
1281         int err;
1282
1283         if (!spi->irq) {
1284                 dev_dbg(&spi->dev, "no IRQ?\n");
1285                 return -EINVAL;
1286         }
1287
1288         /* don't exceed max specified sample rate */
1289         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1290                 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1291                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1292                 return -EINVAL;
1293         }
1294
1295         /*
1296          * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1297          * that even if the hardware can do that, the SPI controller driver
1298          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1299          */
1300         spi->bits_per_word = 8;
1301         spi->mode = SPI_MODE_0;
1302         err = spi_setup(spi);
1303         if (err < 0)
1304                 return err;
1305
1306         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1307         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1308         input_dev = input_allocate_device();
1309         if (!ts || !packet || !input_dev) {
1310                 err = -ENOMEM;
1311                 goto err_free_mem;
1312         }
1313
1314         spi_set_drvdata(spi, ts);
1315
1316         ts->packet = packet;
1317         ts->spi = spi;
1318         ts->input = input_dev;
1319
1320         mutex_init(&ts->lock);
1321         init_waitqueue_head(&ts->wait);
1322
1323         pdata = dev_get_platdata(&spi->dev);
1324         if (!pdata) {
1325                 pdata = ads7846_probe_dt(&spi->dev);
1326                 if (IS_ERR(pdata)) {
1327                         err = PTR_ERR(pdata);
1328                         goto err_free_mem;
1329                 }
1330         }
1331
1332         ts->model = pdata->model ? : 7846;
1333         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1334         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1335         ts->vref_mv = pdata->vref_mv;
1336
1337         if (pdata->filter != NULL) {
1338                 if (pdata->filter_init != NULL) {
1339                         err = pdata->filter_init(pdata, &ts->filter_data);
1340                         if (err < 0)
1341                                 goto err_free_mem;
1342                 }
1343                 ts->filter = pdata->filter;
1344                 ts->filter_cleanup = pdata->filter_cleanup;
1345         } else if (pdata->debounce_max) {
1346                 ts->debounce_max = pdata->debounce_max;
1347                 if (ts->debounce_max < 2)
1348                         ts->debounce_max = 2;
1349                 ts->debounce_tol = pdata->debounce_tol;
1350                 ts->debounce_rep = pdata->debounce_rep;
1351                 ts->filter = ads7846_debounce_filter;
1352                 ts->filter_data = ts;
1353         } else {
1354                 ts->filter = ads7846_no_filter;
1355         }
1356
1357         err = ads7846_setup_pendown(spi, ts, pdata);
1358         if (err)
1359                 goto err_cleanup_filter;
1360
1361         if (pdata->penirq_recheck_delay_usecs)
1362                 ts->penirq_recheck_delay_usecs =
1363                                 pdata->penirq_recheck_delay_usecs;
1364
1365         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1366
1367         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1368         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1369
1370         input_dev->name = ts->name;
1371         input_dev->phys = ts->phys;
1372         input_dev->dev.parent = &spi->dev;
1373
1374         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1375         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1376         input_set_abs_params(input_dev, ABS_X,
1377                         pdata->x_min ? : 0,
1378                         pdata->x_max ? : MAX_12BIT,
1379                         0, 0);
1380         input_set_abs_params(input_dev, ABS_Y,
1381                         pdata->y_min ? : 0,
1382                         pdata->y_max ? : MAX_12BIT,
1383                         0, 0);
1384         input_set_abs_params(input_dev, ABS_PRESSURE,
1385                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1386
1387         /*
1388          * Parse common framework properties. Must be done here to ensure the
1389          * correct behaviour in case of using the legacy vendor bindings. The
1390          * general binding value overrides the vendor specific one.
1391          */
1392         touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1393         ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1394
1395         /*
1396          * Check if legacy ti,swap-xy binding is used instead of
1397          * touchscreen-swapped-x-y
1398          */
1399         if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1400                 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1401                 ts->core_prop.swap_x_y = true;
1402         }
1403
1404         ads7846_setup_spi_msg(ts, pdata);
1405
1406         ts->reg = regulator_get(&spi->dev, "vcc");
1407         if (IS_ERR(ts->reg)) {
1408                 err = PTR_ERR(ts->reg);
1409                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1410                 goto err_free_gpio;
1411         }
1412
1413         err = regulator_enable(ts->reg);
1414         if (err) {
1415                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1416                 goto err_put_regulator;
1417         }
1418
1419         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1420         irq_flags |= IRQF_ONESHOT;
1421
1422         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1423                                    irq_flags, spi->dev.driver->name, ts);
1424         if (err && !pdata->irq_flags) {
1425                 dev_info(&spi->dev,
1426                         "trying pin change workaround on irq %d\n", spi->irq);
1427                 irq_flags |= IRQF_TRIGGER_RISING;
1428                 err = request_threaded_irq(spi->irq,
1429                                   ads7846_hard_irq, ads7846_irq,
1430                                   irq_flags, spi->dev.driver->name, ts);
1431         }
1432
1433         if (err) {
1434                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1435                 goto err_disable_regulator;
1436         }
1437
1438         err = ads784x_hwmon_register(spi, ts);
1439         if (err)
1440                 goto err_free_irq;
1441
1442         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1443
1444         /*
1445          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1446          * the touchscreen, in case it's not connected.
1447          */
1448         if (ts->model == 7845)
1449                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1450         else
1451                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1452
1453         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1454         if (err)
1455                 goto err_remove_hwmon;
1456
1457         err = input_register_device(input_dev);
1458         if (err)
1459                 goto err_remove_attr_group;
1460
1461         device_init_wakeup(&spi->dev, pdata->wakeup);
1462
1463         /*
1464          * If device does not carry platform data we must have allocated it
1465          * when parsing DT data.
1466          */
1467         if (!dev_get_platdata(&spi->dev))
1468                 devm_kfree(&spi->dev, (void *)pdata);
1469
1470         return 0;
1471
1472  err_remove_attr_group:
1473         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1474  err_remove_hwmon:
1475         ads784x_hwmon_unregister(spi, ts);
1476  err_free_irq:
1477         free_irq(spi->irq, ts);
1478  err_disable_regulator:
1479         regulator_disable(ts->reg);
1480  err_put_regulator:
1481         regulator_put(ts->reg);
1482  err_free_gpio:
1483         if (!ts->get_pendown_state)
1484                 gpio_free(ts->gpio_pendown);
1485  err_cleanup_filter:
1486         if (ts->filter_cleanup)
1487                 ts->filter_cleanup(ts->filter_data);
1488  err_free_mem:
1489         input_free_device(input_dev);
1490         kfree(packet);
1491         kfree(ts);
1492         return err;
1493 }
1494
1495 static int ads7846_remove(struct spi_device *spi)
1496 {
1497         struct ads7846 *ts = spi_get_drvdata(spi);
1498
1499         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1500
1501         ads7846_disable(ts);
1502         free_irq(ts->spi->irq, ts);
1503
1504         input_unregister_device(ts->input);
1505
1506         ads784x_hwmon_unregister(spi, ts);
1507
1508         regulator_put(ts->reg);
1509
1510         if (!ts->get_pendown_state) {
1511                 /*
1512                  * If we are not using specialized pendown method we must
1513                  * have been relying on gpio we set up ourselves.
1514                  */
1515                 gpio_free(ts->gpio_pendown);
1516         }
1517
1518         if (ts->filter_cleanup)
1519                 ts->filter_cleanup(ts->filter_data);
1520
1521         kfree(ts->packet);
1522         kfree(ts);
1523
1524         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1525
1526         return 0;
1527 }
1528
1529 static struct spi_driver ads7846_driver = {
1530         .driver = {
1531                 .name   = "ads7846",
1532                 .pm     = &ads7846_pm,
1533                 .of_match_table = of_match_ptr(ads7846_dt_ids),
1534         },
1535         .probe          = ads7846_probe,
1536         .remove         = ads7846_remove,
1537 };
1538
1539 module_spi_driver(ads7846_driver);
1540
1541 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1542 MODULE_LICENSE("GPL");
1543 MODULE_ALIAS("spi:ads7846");