drivers/input/touchscreen/ads7846.c

   1 /*
   2  * ADS7846 based touchscreen and sensor driver
   3  *
   4  * Copyright (c) 2005 David Brownell
   5  * Copyright (c) 2006 Nokia Corporation
   6  * Various changes: Imre Deak <imre.deak@nokia.com>
   7  *
   8  * Using code from:
   9  *  - corgi_ts.c
  10  *      Copyright (C) 2004-2005 Richard Purdie
  11  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  12  *      Copyright (C) 2002 MontaVista Software
  13  *      Copyright (C) 2004 Texas Instruments
  14  *      Copyright (C) 2005 Dirk Behme
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2 as
  18  *  published by the Free Software Foundation.
  19  */
  20 #include <linux/types.h>
  21 #include <linux/hwmon.h>
  22 #include <linux/err.h>
  23 #include <linux/sched.h>
  24 #include <linux/delay.h>
  25 #include <linux/input.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/slab.h>
  28 #include <linux/pm.h>
  29 #include <linux/of.h>
  30 #include <linux/of_gpio.h>
  31 #include <linux/of_device.h>
  32 #include <linux/gpio.h>
  33 #include <linux/spi/spi.h>
  34 #include <linux/spi/ads7846.h>
  35 #include <linux/regulator/consumer.h>
  36 #include <linux/module.h>
  37 #include <asm/irq.h>
  38
  39 /*
  40  * This code has been heavily tested on a Nokia 770, and lightly
  41  * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
  42  * TSC2046 is just newer ads7846 silicon.
  43  * Support for ads7843 tested on Atmel at91sam926x-EK.
  44  * Support for ads7845 has only been stubbed in.
  45  * Support for Analog Devices AD7873 and AD7843 tested.
  46  *
  47  * IRQ handling needs a workaround because of a shortcoming in handling
  48  * edge triggered IRQs on some platforms like the OMAP1/2. These
  49  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
  50  * have to maintain our own SW IRQ disabled status. This should be
  51  * removed as soon as the affected platform's IRQ handling is fixed.
  52  *
  53  * App note sbaa036 talks in more detail about accurate sampling...
  54  * that ought to help in situations like LCDs inducing noise (which
  55  * can also be helped by using synch signals) and more generally.
  56  * This driver tries to utilize the measures described in the app
  57  * note. The strength of filtering can be set in the board-* specific
  58  * files.
  59  */
  60
  61 #define TS_POLL_DELAY   1       /* ms delay before the first sample */
  62 #define TS_POLL_PERIOD  5       /* ms delay between samples */
  63
  64 /* this driver doesn't aim at the peak continuous sample rate */
  65 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
  66
  67 struct ts_event {
  68         /*
  69          * For portability, we can't read 12 bit values using SPI (which
  70          * would make the controller deliver them as native byte order u16
  71          * with msbs zeroed).  Instead, we read them as two 8-bit values,
  72          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
  73          */
  74         u16     x;
  75         u16     y;
  76         u16     z1, z2;
  77         bool    ignore;
  78         u8      x_buf[3];
  79         u8      y_buf[3];
  80 };
  81
  82 /*
  83  * We allocate this separately to avoid cache line sharing issues when
  84  * driver is used with DMA-based SPI controllers (like atmel_spi) on
  85  * systems where main memory is not DMA-coherent (most non-x86 boards).
  86  */
  87 struct ads7846_packet {
  88         u8                      read_x, read_y, read_z1, read_z2, pwrdown;
  89         u16                     dummy;          /* for the pwrdown read */
  90         struct ts_event         tc;
  91         /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
  92         u8                      read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
  93 };
  94
  95 struct ads7846 {
  96         struct input_dev        *input;
  97         char                    phys[32];
  98         char                    name[32];
  99
 100         struct spi_device       *spi;
 101         struct regulator        *reg;
 102
 103 #if IS_ENABLED(CONFIG_HWMON)
 104         struct device           *hwmon;
 105 #endif
 106
 107         u16                     model;
 108         u16                     vref_mv;
 109         u16                     vref_delay_usecs;
 110         u16                     x_plate_ohms;
 111         u16                     pressure_max;
 112
 113         bool                    swap_xy;
 114         bool                    use_internal;
 115
 116         struct ads7846_packet   *packet;
 117
 118         struct spi_transfer     xfer[18];
 119         struct spi_message      msg[5];
 120         int                     msg_count;
 121         wait_queue_head_t       wait;
 122
 123         bool                    pendown;
 124
 125         int                     read_cnt;
 126         int                     read_rep;
 127         int                     last_read;
 128
 129         u16                     debounce_max;
 130         u16                     debounce_tol;
 131         u16                     debounce_rep;
 132
 133         u16                     penirq_recheck_delay_usecs;
 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_usecs = ts->vref_delay_usecs;
 337                 spi_message_add_tail(&req->xfer[1], &req->msg);
 338
 339                 /* Enable reference voltage */
 340                 command |= ADS_PD10_REF_ON;
 341         }
 342
 343         /* Enable ADC in every case */
 344         command |= ADS_PD10_ADC_ON;
 345
 346         /* take sample */
 347         req->command = (u8) command;
 348         req->xfer[2].tx_buf = &req->command;
 349         req->xfer[2].len = 1;
 350         spi_message_add_tail(&req->xfer[2], &req->msg);
 351
 352         req->xfer[3].rx_buf = &req->sample;
 353         req->xfer[3].len = 2;
 354         spi_message_add_tail(&req->xfer[3], &req->msg);
 355
 356         /* REVISIT:  take a few more samples, and compare ... */
 357
 358         /* converter in low power mode & enable PENIRQ */
 359         req->ref_off = PWRDOWN;
 360         req->xfer[4].tx_buf = &req->ref_off;
 361         req->xfer[4].len = 1;
 362         spi_message_add_tail(&req->xfer[4], &req->msg);
 363
 364         req->xfer[5].rx_buf = &req->scratch;
 365         req->xfer[5].len = 2;
 366         CS_CHANGE(req->xfer[5]);
 367         spi_message_add_tail(&req->xfer[5], &req->msg);
 368
 369         mutex_lock(&ts->lock);
 370         ads7846_stop(ts);
 371         status = spi_sync(spi, &req->msg);
 372         ads7846_restart(ts);
 373         mutex_unlock(&ts->lock);
 374
 375         if (status == 0) {
 376                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
 377                 status = be16_to_cpu(req->sample);
 378                 status = status >> 3;
 379                 status &= 0x0fff;
 380         }
 381
 382         kfree(req);
 383         return status;
 384 }
 385
 386 static int ads7845_read12_ser(struct device *dev, unsigned command)
 387 {
 388         struct spi_device *spi = to_spi_device(dev);
 389         struct ads7846 *ts = dev_get_drvdata(dev);
 390         struct ads7845_ser_req *req;
 391         int status;
 392
 393         req = kzalloc(sizeof *req, GFP_KERNEL);
 394         if (!req)
 395                 return -ENOMEM;
 396
 397         spi_message_init(&req->msg);
 398
 399         req->command[0] = (u8) command;
 400         req->xfer[0].tx_buf = req->command;
 401         req->xfer[0].rx_buf = req->sample;
 402         req->xfer[0].len = 3;
 403         spi_message_add_tail(&req->xfer[0], &req->msg);
 404
 405         mutex_lock(&ts->lock);
 406         ads7846_stop(ts);
 407         status = spi_sync(spi, &req->msg);
 408         ads7846_restart(ts);
 409         mutex_unlock(&ts->lock);
 410
 411         if (status == 0) {
 412                 /* BE12 value, then padding */
 413                 status = be16_to_cpu(*((u16 *)&req->sample[1]));
 414                 status = status >> 3;
 415                 status &= 0x0fff;
 416         }
 417
 418         kfree(req);
 419         return status;
 420 }
 421
 422 #if IS_ENABLED(CONFIG_HWMON)
 423
 424 #define SHOW(name, var, adjust) static ssize_t \
 425 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 426 { \
 427         struct ads7846 *ts = dev_get_drvdata(dev); \
 428         ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
 429                         READ_12BIT_SER(var)); \
 430         if (v < 0) \
 431                 return v; \
 432         return sprintf(buf, "%u\n", adjust(ts, v)); \
 433 } \
 434 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 435
 436
 437 /* Sysfs conventions report temperatures in millidegrees Celsius.
 438  * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
 439  * accuracy scheme without calibration data.  For now we won't try either;
 440  * userspace sees raw sensor values, and must scale/calibrate appropriately.
 441  */
 442 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
 443 {
 444         return v;
 445 }
 446
 447 SHOW(temp0, temp0, null_adjust)         /* temp1_input */
 448 SHOW(temp1, temp1, null_adjust)         /* temp2_input */
 449
 450
 451 /* sysfs conventions report voltages in millivolts.  We can convert voltages
 452  * if we know vREF.  userspace may need to scale vAUX to match the board's
 453  * external resistors; we assume that vBATT only uses the internal ones.
 454  */
 455 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
 456 {
 457         unsigned retval = v;
 458
 459         /* external resistors may scale vAUX into 0..vREF */
 460         retval *= ts->vref_mv;
 461         retval = retval >> 12;
 462
 463         return retval;
 464 }
 465
 466 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
 467 {
 468         unsigned retval = vaux_adjust(ts, v);
 469
 470         /* ads7846 has a resistor ladder to scale this signal down */
 471         if (ts->model == 7846)
 472                 retval *= 4;
 473
 474         return retval;
 475 }
 476
 477 SHOW(in0_input, vaux, vaux_adjust)
 478 SHOW(in1_input, vbatt, vbatt_adjust)
 479
 480 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
 481                                   int index)
 482 {
 483         struct device *dev = container_of(kobj, struct device, kobj);
 484         struct ads7846 *ts = dev_get_drvdata(dev);
 485
 486         if (ts->model == 7843 && index < 2)     /* in0, in1 */
 487                 return 0;
 488         if (ts->model == 7845 && index != 2)    /* in0 */
 489                 return 0;
 490
 491         return attr->mode;
 492 }
 493
 494 static struct attribute *ads7846_attributes[] = {
 495         &dev_attr_temp0.attr,           /* 0 */
 496         &dev_attr_temp1.attr,           /* 1 */
 497         &dev_attr_in0_input.attr,       /* 2 */
 498         &dev_attr_in1_input.attr,       /* 3 */
 499         NULL,
 500 };
 501
 502 static struct attribute_group ads7846_attr_group = {
 503         .attrs = ads7846_attributes,
 504         .is_visible = ads7846_is_visible,
 505 };
 506 __ATTRIBUTE_GROUPS(ads7846_attr);
 507
 508 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 509 {
 510         /* hwmon sensors need a reference voltage */
 511         switch (ts->model) {
 512         case 7846:
 513                 if (!ts->vref_mv) {
 514                         dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
 515                         ts->vref_mv = 2500;
 516                         ts->use_internal = true;
 517                 }
 518                 break;
 519         case 7845:
 520         case 7843:
 521                 if (!ts->vref_mv) {
 522                         dev_warn(&spi->dev,
 523                                 "external vREF for ADS%d not specified\n",
 524                                 ts->model);
 525                         return 0;
 526                 }
 527                 break;
 528         }
 529
 530         ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
 531                                                       ts, ads7846_attr_groups);
 532         if (IS_ERR(ts->hwmon))
 533                 return PTR_ERR(ts->hwmon);
 534
 535         return 0;
 536 }
 537
 538 static void ads784x_hwmon_unregister(struct spi_device *spi,
 539                                      struct ads7846 *ts)
 540 {
 541         if (ts->hwmon)
 542                 hwmon_device_unregister(ts->hwmon);
 543 }
 544
 545 #else
 546 static inline int ads784x_hwmon_register(struct spi_device *spi,
 547                                          struct ads7846 *ts)
 548 {
 549         return 0;
 550 }
 551
 552 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
 553                                             struct ads7846 *ts)
 554 {
 555 }
 556 #endif
 557
 558 static ssize_t ads7846_pen_down_show(struct device *dev,
 559                                      struct device_attribute *attr, char *buf)
 560 {
 561         struct ads7846 *ts = dev_get_drvdata(dev);
 562
 563         return sprintf(buf, "%u\n", ts->pendown);
 564 }
 565
 566 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
 567
 568 static ssize_t ads7846_disable_show(struct device *dev,
 569                                      struct device_attribute *attr, char *buf)
 570 {
 571         struct ads7846 *ts = dev_get_drvdata(dev);
 572
 573         return sprintf(buf, "%u\n", ts->disabled);
 574 }
 575
 576 static ssize_t ads7846_disable_store(struct device *dev,
 577                                      struct device_attribute *attr,
 578                                      const char *buf, size_t count)
 579 {
 580         struct ads7846 *ts = dev_get_drvdata(dev);
 581         unsigned int i;
 582         int err;
 583
 584         err = kstrtouint(buf, 10, &i);
 585         if (err)
 586                 return err;
 587
 588         if (i)
 589                 ads7846_disable(ts);
 590         else
 591                 ads7846_enable(ts);
 592
 593         return count;
 594 }
 595
 596 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 597
 598 static struct attribute *ads784x_attributes[] = {
 599         &dev_attr_pen_down.attr,
 600         &dev_attr_disable.attr,
 601         NULL,
 602 };
 603
 604 static struct attribute_group ads784x_attr_group = {
 605         .attrs = ads784x_attributes,
 606 };
 607
 608 /*--------------------------------------------------------------------------*/
 609
 610 static int get_pendown_state(struct ads7846 *ts)
 611 {
 612         if (ts->get_pendown_state)
 613                 return ts->get_pendown_state();
 614
 615         return !gpio_get_value(ts->gpio_pendown);
 616 }
 617
 618 static void null_wait_for_sync(void)
 619 {
 620 }
 621
 622 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
 623 {
 624         struct ads7846 *ts = ads;
 625
 626         if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 627                 /* Start over collecting consistent readings. */
 628                 ts->read_rep = 0;
 629                 /*
 630                  * Repeat it, if this was the first read or the read
 631                  * wasn't consistent enough.
 632                  */
 633                 if (ts->read_cnt < ts->debounce_max) {
 634                         ts->last_read = *val;
 635                         ts->read_cnt++;
 636                         return ADS7846_FILTER_REPEAT;
 637                 } else {
 638                         /*
 639                          * Maximum number of debouncing reached and still
 640                          * not enough number of consistent readings. Abort
 641                          * the whole sample, repeat it in the next sampling
 642                          * period.
 643                          */
 644                         ts->read_cnt = 0;
 645                         return ADS7846_FILTER_IGNORE;
 646                 }
 647         } else {
 648                 if (++ts->read_rep > ts->debounce_rep) {
 649                         /*
 650                          * Got a good reading for this coordinate,
 651                          * go for the next one.
 652                          */
 653                         ts->read_cnt = 0;
 654                         ts->read_rep = 0;
 655                         return ADS7846_FILTER_OK;
 656                 } else {
 657                         /* Read more values that are consistent. */
 658                         ts->read_cnt++;
 659                         return ADS7846_FILTER_REPEAT;
 660                 }
 661         }
 662 }
 663
 664 static int ads7846_no_filter(void *ads, int data_idx, int *val)
 665 {
 666         return ADS7846_FILTER_OK;
 667 }
 668
 669 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
 670 {
 671         struct spi_transfer *t =
 672                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 673
 674         if (ts->model == 7845) {
 675                 return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3;
 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                 return be16_to_cpup((__be16 *)t->rx_buf) >> 3;
 682         }
 683 }
 684
 685 static void ads7846_update_value(struct spi_message *m, int val)
 686 {
 687         struct spi_transfer *t =
 688                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 689
 690         *(u16 *)t->rx_buf = val;
 691 }
 692
 693 static void ads7846_read_state(struct ads7846 *ts)
 694 {
 695         struct ads7846_packet *packet = ts->packet;
 696         struct spi_message *m;
 697         int msg_idx = 0;
 698         int val;
 699         int action;
 700         int error;
 701
 702         while (msg_idx < ts->msg_count) {
 703
 704                 ts->wait_for_sync();
 705
 706                 m = &ts->msg[msg_idx];
 707                 error = spi_sync(ts->spi, m);
 708                 if (error) {
 709                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 710                         packet->tc.ignore = true;
 711                         return;
 712                 }
 713
 714                 /*
 715                  * Last message is power down request, no need to convert
 716                  * or filter the value.
 717                  */
 718                 if (msg_idx < ts->msg_count - 1) {
 719
 720                         val = ads7846_get_value(ts, m);
 721
 722                         action = ts->filter(ts->filter_data, msg_idx, &val);
 723                         switch (action) {
 724                         case ADS7846_FILTER_REPEAT:
 725                                 continue;
 726
 727                         case ADS7846_FILTER_IGNORE:
 728                                 packet->tc.ignore = true;
 729                                 msg_idx = ts->msg_count - 1;
 730                                 continue;
 731
 732                         case ADS7846_FILTER_OK:
 733                                 ads7846_update_value(m, val);
 734                                 packet->tc.ignore = false;
 735                                 msg_idx++;
 736                                 break;
 737
 738                         default:
 739                                 BUG();
 740                         }
 741                 } else {
 742                         msg_idx++;
 743                 }
 744         }
 745 }
 746
 747 static void ads7846_report_state(struct ads7846 *ts)
 748 {
 749         struct ads7846_packet *packet = ts->packet;
 750         unsigned int Rt;
 751         u16 x, y, z1, z2;
 752
 753         /*
 754          * ads7846_get_value() does in-place conversion (including byte swap)
 755          * from on-the-wire format as part of debouncing to get stable
 756          * readings.
 757          */
 758         if (ts->model == 7845) {
 759                 x = *(u16 *)packet->tc.x_buf;
 760                 y = *(u16 *)packet->tc.y_buf;
 761                 z1 = 0;
 762                 z2 = 0;
 763         } else {
 764                 x = packet->tc.x;
 765                 y = packet->tc.y;
 766                 z1 = packet->tc.z1;
 767                 z2 = packet->tc.z2;
 768         }
 769
 770         /* range filtering */
 771         if (x == MAX_12BIT)
 772                 x = 0;
 773
 774         if (ts->model == 7843) {
 775                 Rt = ts->pressure_max / 2;
 776         } else if (ts->model == 7845) {
 777                 if (get_pendown_state(ts))
 778                         Rt = ts->pressure_max / 2;
 779                 else
 780                         Rt = 0;
 781                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 782         } else if (likely(x && z1)) {
 783                 /* compute touch pressure resistance using equation #2 */
 784                 Rt = z2;
 785                 Rt -= z1;
 786                 Rt *= x;
 787                 Rt *= ts->x_plate_ohms;
 788                 Rt /= z1;
 789                 Rt = (Rt + 2047) >> 12;
 790         } else {
 791                 Rt = 0;
 792         }
 793
 794         /*
 795          * Sample found inconsistent by debouncing or pressure is beyond
 796          * the maximum. Don't report it to user space, repeat at least
 797          * once more the measurement
 798          */
 799         if (packet->tc.ignore || Rt > ts->pressure_max) {
 800                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 801                          packet->tc.ignore, Rt);
 802                 return;
 803         }
 804
 805         /*
 806          * Maybe check the pendown state before reporting. This discards
 807          * false readings when the pen is lifted.
 808          */
 809         if (ts->penirq_recheck_delay_usecs) {
 810                 udelay(ts->penirq_recheck_delay_usecs);
 811                 if (!get_pendown_state(ts))
 812                         Rt = 0;
 813         }
 814
 815         /*
 816          * NOTE: We can't rely on the pressure to determine the pen down
 817          * state, even this controller has a pressure sensor. The pressure
 818          * value can fluctuate for quite a while after lifting the pen and
 819          * in some cases may not even settle at the expected value.
 820          *
 821          * The only safe way to check for the pen up condition is in the
 822          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 823          */
 824         if (Rt) {
 825                 struct input_dev *input = ts->input;
 826
 827                 if (ts->swap_xy)
 828                         swap(x, y);
 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                 input_report_abs(input, ABS_X, x);
 837                 input_report_abs(input, ABS_Y, y);
 838                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 839
 840                 input_sync(input);
 841                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
 842         }
 843 }
 844
 845 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 846 {
 847         struct ads7846 *ts = handle;
 848
 849         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 850 }
 851
 852
 853 static irqreturn_t ads7846_irq(int irq, void *handle)
 854 {
 855         struct ads7846 *ts = handle;
 856
 857         /* Start with a small delay before checking pendown state */
 858         msleep(TS_POLL_DELAY);
 859
 860         while (!ts->stopped && get_pendown_state(ts)) {
 861
 862                 /* pen is down, continue with the measurement */
 863                 ads7846_read_state(ts);
 864
 865                 if (!ts->stopped)
 866                         ads7846_report_state(ts);
 867
 868                 wait_event_timeout(ts->wait, ts->stopped,
 869                                    msecs_to_jiffies(TS_POLL_PERIOD));
 870         }
 871
 872         if (ts->pendown) {
 873                 struct input_dev *input = ts->input;
 874
 875                 input_report_key(input, BTN_TOUCH, 0);
 876                 input_report_abs(input, ABS_PRESSURE, 0);
 877                 input_sync(input);
 878
 879                 ts->pendown = false;
 880                 dev_vdbg(&ts->spi->dev, "UP\n");
 881         }
 882
 883         return IRQ_HANDLED;
 884 }
 885
 886 static int __maybe_unused ads7846_suspend(struct device *dev)
 887 {
 888         struct ads7846 *ts = dev_get_drvdata(dev);
 889
 890         mutex_lock(&ts->lock);
 891
 892         if (!ts->suspended) {
 893
 894                 if (!ts->disabled)
 895                         __ads7846_disable(ts);
 896
 897                 if (device_may_wakeup(&ts->spi->dev))
 898                         enable_irq_wake(ts->spi->irq);
 899
 900                 ts->suspended = true;
 901         }
 902
 903         mutex_unlock(&ts->lock);
 904
 905         return 0;
 906 }
 907
 908 static int __maybe_unused ads7846_resume(struct device *dev)
 909 {
 910         struct ads7846 *ts = dev_get_drvdata(dev);
 911
 912         mutex_lock(&ts->lock);
 913
 914         if (ts->suspended) {
 915
 916                 ts->suspended = false;
 917
 918                 if (device_may_wakeup(&ts->spi->dev))
 919                         disable_irq_wake(ts->spi->irq);
 920
 921                 if (!ts->disabled)
 922                         __ads7846_enable(ts);
 923         }
 924
 925         mutex_unlock(&ts->lock);
 926
 927         return 0;
 928 }
 929
 930 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 931
 932 static int ads7846_setup_pendown(struct spi_device *spi,
 933                                  struct ads7846 *ts,
 934                                  const struct ads7846_platform_data *pdata)
 935 {
 936         int err;
 937
 938         /*
 939          * REVISIT when the irq can be triggered active-low, or if for some
 940          * reason the touchscreen isn't hooked up, we don't need to access
 941          * the pendown state.
 942          */
 943
 944         if (pdata->get_pendown_state) {
 945                 ts->get_pendown_state = pdata->get_pendown_state;
 946         } else if (gpio_is_valid(pdata->gpio_pendown)) {
 947
 948                 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
 949                                        "ads7846_pendown");
 950                 if (err) {
 951                         dev_err(&spi->dev,
 952                                 "failed to request/setup pendown GPIO%d: %d\n",
 953                                 pdata->gpio_pendown, err);
 954                         return err;
 955                 }
 956
 957                 ts->gpio_pendown = pdata->gpio_pendown;
 958
 959                 if (pdata->gpio_pendown_debounce)
 960                         gpio_set_debounce(pdata->gpio_pendown,
 961                                           pdata->gpio_pendown_debounce);
 962         } else {
 963                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 964                 return -EINVAL;
 965         }
 966
 967         return 0;
 968 }
 969
 970 /*
 971  * Set up the transfers to read touchscreen state; this assumes we
 972  * use formula #2 for pressure, not #3.
 973  */
 974 static void ads7846_setup_spi_msg(struct ads7846 *ts,
 975                                   const struct ads7846_platform_data *pdata)
 976 {
 977         struct spi_message *m = &ts->msg[0];
 978         struct spi_transfer *x = ts->xfer;
 979         struct ads7846_packet *packet = ts->packet;
 980         int vref = pdata->keep_vref_on;
 981
 982         if (ts->model == 7873) {
 983                 /*
 984                  * The AD7873 is almost identical to the ADS7846
 985                  * keep VREF off during differential/ratiometric
 986                  * conversion modes.
 987                  */
 988                 ts->model = 7846;
 989                 vref = 0;
 990         }
 991
 992         ts->msg_count = 1;
 993         spi_message_init(m);
 994         m->context = ts;
 995
 996         if (ts->model == 7845) {
 997                 packet->read_y_cmd[0] = READ_Y(vref);
 998                 packet->read_y_cmd[1] = 0;
 999                 packet->read_y_cmd[2] = 0;
1000                 x->tx_buf = &packet->read_y_cmd[0];
1001                 x->rx_buf = &packet->tc.y_buf[0];
1002                 x->len = 3;
1003                 spi_message_add_tail(x, m);
1004         } else {
1005                 /* y- still on; turn on only y+ (and ADC) */
1006                 packet->read_y = READ_Y(vref);
1007                 x->tx_buf = &packet->read_y;
1008                 x->len = 1;
1009                 spi_message_add_tail(x, m);
1010
1011                 x++;
1012                 x->rx_buf = &packet->tc.y;
1013                 x->len = 2;
1014                 spi_message_add_tail(x, m);
1015         }
1016
1017         /*
1018          * The first sample after switching drivers can be low quality;
1019          * optionally discard it, using a second one after the signals
1020          * have had enough time to stabilize.
1021          */
1022         if (pdata->settle_delay_usecs) {
1023                 x->delay_usecs = pdata->settle_delay_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_usecs = pdata->settle_delay_usecs;
1067
1068                 x++;
1069                 x->tx_buf = &packet->read_x;
1070                 x->len = 1;
1071                 spi_message_add_tail(x, m);
1072
1073                 x++;
1074                 x->rx_buf = &packet->tc.x;
1075                 x->len = 2;
1076                 spi_message_add_tail(x, m);
1077         }
1078
1079         /* turn y+ off, x- on; we'll use formula #2 */
1080         if (ts->model == 7846) {
1081                 ts->msg_count++;
1082                 m++;
1083                 spi_message_init(m);
1084                 m->context = ts;
1085
1086                 x++;
1087                 packet->read_z1 = READ_Z1(vref);
1088                 x->tx_buf = &packet->read_z1;
1089                 x->len = 1;
1090                 spi_message_add_tail(x, m);
1091
1092                 x++;
1093                 x->rx_buf = &packet->tc.z1;
1094                 x->len = 2;
1095                 spi_message_add_tail(x, m);
1096
1097                 /* ... maybe discard first sample ... */
1098                 if (pdata->settle_delay_usecs) {
1099                         x->delay_usecs = pdata->settle_delay_usecs;
1100
1101                         x++;
1102                         x->tx_buf = &packet->read_z1;
1103                         x->len = 1;
1104                         spi_message_add_tail(x, m);
1105
1106                         x++;
1107                         x->rx_buf = &packet->tc.z1;
1108                         x->len = 2;
1109                         spi_message_add_tail(x, m);
1110                 }
1111
1112                 ts->msg_count++;
1113                 m++;
1114                 spi_message_init(m);
1115                 m->context = ts;
1116
1117                 x++;
1118                 packet->read_z2 = READ_Z2(vref);
1119                 x->tx_buf = &packet->read_z2;
1120                 x->len = 1;
1121                 spi_message_add_tail(x, m);
1122
1123                 x++;
1124                 x->rx_buf = &packet->tc.z2;
1125                 x->len = 2;
1126                 spi_message_add_tail(x, m);
1127
1128                 /* ... maybe discard first sample ... */
1129                 if (pdata->settle_delay_usecs) {
1130                         x->delay_usecs = pdata->settle_delay_usecs;
1131
1132                         x++;
1133                         x->tx_buf = &packet->read_z2;
1134                         x->len = 1;
1135                         spi_message_add_tail(x, m);
1136
1137                         x++;
1138                         x->rx_buf = &packet->tc.z2;
1139                         x->len = 2;
1140                         spi_message_add_tail(x, m);
1141                 }
1142         }
1143
1144         /* power down */
1145         ts->msg_count++;
1146         m++;
1147         spi_message_init(m);
1148         m->context = ts;
1149
1150         if (ts->model == 7845) {
1151                 x++;
1152                 packet->pwrdown_cmd[0] = PWRDOWN;
1153                 packet->pwrdown_cmd[1] = 0;
1154                 packet->pwrdown_cmd[2] = 0;
1155                 x->tx_buf = &packet->pwrdown_cmd[0];
1156                 x->len = 3;
1157         } else {
1158                 x++;
1159                 packet->pwrdown = PWRDOWN;
1160                 x->tx_buf = &packet->pwrdown;
1161                 x->len = 1;
1162                 spi_message_add_tail(x, m);
1163
1164                 x++;
1165                 x->rx_buf = &packet->dummy;
1166                 x->len = 2;
1167         }
1168
1169         CS_CHANGE(*x);
1170         spi_message_add_tail(x, m);
1171 }
1172
1173 #ifdef CONFIG_OF
1174 static const struct of_device_id ads7846_dt_ids[] = {
1175         { .compatible = "ti,tsc2046",   .data = (void *) 7846 },
1176         { .compatible = "ti,ads7843",   .data = (void *) 7843 },
1177         { .compatible = "ti,ads7845",   .data = (void *) 7845 },
1178         { .compatible = "ti,ads7846",   .data = (void *) 7846 },
1179         { .compatible = "ti,ads7873",   .data = (void *) 7873 },
1180         { }
1181 };
1182 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1183
1184 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1185 {
1186         struct ads7846_platform_data *pdata;
1187         struct device_node *node = dev->of_node;
1188         const struct of_device_id *match;
1189
1190         if (!node) {
1191                 dev_err(dev, "Device does not have associated DT data\n");
1192                 return ERR_PTR(-EINVAL);
1193         }
1194
1195         match = of_match_device(ads7846_dt_ids, dev);
1196         if (!match) {
1197                 dev_err(dev, "Unknown device model\n");
1198                 return ERR_PTR(-EINVAL);
1199         }
1200
1201         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1202         if (!pdata)
1203                 return ERR_PTR(-ENOMEM);
1204
1205         pdata->model = (unsigned long)match->data;
1206
1207         of_property_read_u16(node, "ti,vref-delay-usecs",
1208                              &pdata->vref_delay_usecs);
1209         of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1210         pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1211
1212         pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1213
1214         of_property_read_u16(node, "ti,settle-delay-usec",
1215                              &pdata->settle_delay_usecs);
1216         of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1217                              &pdata->penirq_recheck_delay_usecs);
1218
1219         of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1220         of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1221
1222         of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1223         of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1224         of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1225         of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1226
1227         of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1228         of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1229
1230         of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1231         of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1232         of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1233
1234         of_property_read_u32(node, "ti,pendown-gpio-debounce",
1235                              &pdata->gpio_pendown_debounce);
1236
1237         pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1238                         of_property_read_bool(node, "linux,wakeup");
1239
1240         pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1241
1242         return pdata;
1243 }
1244 #else
1245 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1246 {
1247         dev_err(dev, "no platform data defined\n");
1248         return ERR_PTR(-EINVAL);
1249 }
1250 #endif
1251
1252 static int ads7846_probe(struct spi_device *spi)
1253 {
1254         const struct ads7846_platform_data *pdata;
1255         struct ads7846 *ts;
1256         struct ads7846_packet *packet;
1257         struct input_dev *input_dev;
1258         unsigned long irq_flags;
1259         int err;
1260
1261         if (!spi->irq) {
1262                 dev_dbg(&spi->dev, "no IRQ?\n");
1263                 return -EINVAL;
1264         }
1265
1266         /* don't exceed max specified sample rate */
1267         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1268                 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1269                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1270                 return -EINVAL;
1271         }
1272
1273         /*
1274          * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1275          * that even if the hardware can do that, the SPI controller driver
1276          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1277          */
1278         spi->bits_per_word = 8;
1279         spi->mode = SPI_MODE_0;
1280         err = spi_setup(spi);
1281         if (err < 0)
1282                 return err;
1283
1284         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1285         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1286         input_dev = input_allocate_device();
1287         if (!ts || !packet || !input_dev) {
1288                 err = -ENOMEM;
1289                 goto err_free_mem;
1290         }
1291
1292         spi_set_drvdata(spi, ts);
1293
1294         ts->packet = packet;
1295         ts->spi = spi;
1296         ts->input = input_dev;
1297
1298         mutex_init(&ts->lock);
1299         init_waitqueue_head(&ts->wait);
1300
1301         pdata = dev_get_platdata(&spi->dev);
1302         if (!pdata) {
1303                 pdata = ads7846_probe_dt(&spi->dev);
1304                 if (IS_ERR(pdata)) {
1305                         err = PTR_ERR(pdata);
1306                         goto err_free_mem;
1307                 }
1308         }
1309
1310         ts->model = pdata->model ? : 7846;
1311         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1312         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1313         ts->pressure_max = pdata->pressure_max ? : ~0;
1314
1315         ts->vref_mv = pdata->vref_mv;
1316         ts->swap_xy = pdata->swap_xy;
1317
1318         if (pdata->filter != NULL) {
1319                 if (pdata->filter_init != NULL) {
1320                         err = pdata->filter_init(pdata, &ts->filter_data);
1321                         if (err < 0)
1322                                 goto err_free_mem;
1323                 }
1324                 ts->filter = pdata->filter;
1325                 ts->filter_cleanup = pdata->filter_cleanup;
1326         } else if (pdata->debounce_max) {
1327                 ts->debounce_max = pdata->debounce_max;
1328                 if (ts->debounce_max < 2)
1329                         ts->debounce_max = 2;
1330                 ts->debounce_tol = pdata->debounce_tol;
1331                 ts->debounce_rep = pdata->debounce_rep;
1332                 ts->filter = ads7846_debounce_filter;
1333                 ts->filter_data = ts;
1334         } else {
1335                 ts->filter = ads7846_no_filter;
1336         }
1337
1338         err = ads7846_setup_pendown(spi, ts, pdata);
1339         if (err)
1340                 goto err_cleanup_filter;
1341
1342         if (pdata->penirq_recheck_delay_usecs)
1343                 ts->penirq_recheck_delay_usecs =
1344                                 pdata->penirq_recheck_delay_usecs;
1345
1346         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1347
1348         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1349         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1350
1351         input_dev->name = ts->name;
1352         input_dev->phys = ts->phys;
1353         input_dev->dev.parent = &spi->dev;
1354
1355         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1356         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1357         input_set_abs_params(input_dev, ABS_X,
1358                         pdata->x_min ? : 0,
1359                         pdata->x_max ? : MAX_12BIT,
1360                         0, 0);
1361         input_set_abs_params(input_dev, ABS_Y,
1362                         pdata->y_min ? : 0,
1363                         pdata->y_max ? : MAX_12BIT,
1364                         0, 0);
1365         input_set_abs_params(input_dev, ABS_PRESSURE,
1366                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1367
1368         ads7846_setup_spi_msg(ts, pdata);
1369
1370         ts->reg = regulator_get(&spi->dev, "vcc");
1371         if (IS_ERR(ts->reg)) {
1372                 err = PTR_ERR(ts->reg);
1373                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1374                 goto err_free_gpio;
1375         }
1376
1377         err = regulator_enable(ts->reg);
1378         if (err) {
1379                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1380                 goto err_put_regulator;
1381         }
1382
1383         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1384         irq_flags |= IRQF_ONESHOT;
1385
1386         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1387                                    irq_flags, spi->dev.driver->name, ts);
1388         if (err && !pdata->irq_flags) {
1389                 dev_info(&spi->dev,
1390                         "trying pin change workaround on irq %d\n", spi->irq);
1391                 irq_flags |= IRQF_TRIGGER_RISING;
1392                 err = request_threaded_irq(spi->irq,
1393                                   ads7846_hard_irq, ads7846_irq,
1394                                   irq_flags, spi->dev.driver->name, ts);
1395         }
1396
1397         if (err) {
1398                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1399                 goto err_disable_regulator;
1400         }
1401
1402         err = ads784x_hwmon_register(spi, ts);
1403         if (err)
1404                 goto err_free_irq;
1405
1406         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1407
1408         /*
1409          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1410          * the touchscreen, in case it's not connected.
1411          */
1412         if (ts->model == 7845)
1413                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1414         else
1415                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1416
1417         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1418         if (err)
1419                 goto err_remove_hwmon;
1420
1421         err = input_register_device(input_dev);
1422         if (err)
1423                 goto err_remove_attr_group;
1424
1425         device_init_wakeup(&spi->dev, pdata->wakeup);
1426
1427         /*
1428          * If device does not carry platform data we must have allocated it
1429          * when parsing DT data.
1430          */
1431         if (!dev_get_platdata(&spi->dev))
1432                 devm_kfree(&spi->dev, (void *)pdata);
1433
1434         return 0;
1435
1436  err_remove_attr_group:
1437         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1438  err_remove_hwmon:
1439         ads784x_hwmon_unregister(spi, ts);
1440  err_free_irq:
1441         free_irq(spi->irq, ts);
1442  err_disable_regulator:
1443         regulator_disable(ts->reg);
1444  err_put_regulator:
1445         regulator_put(ts->reg);
1446  err_free_gpio:
1447         if (!ts->get_pendown_state)
1448                 gpio_free(ts->gpio_pendown);
1449  err_cleanup_filter:
1450         if (ts->filter_cleanup)
1451                 ts->filter_cleanup(ts->filter_data);
1452  err_free_mem:
1453         input_free_device(input_dev);
1454         kfree(packet);
1455         kfree(ts);
1456         return err;
1457 }
1458
1459 static int ads7846_remove(struct spi_device *spi)
1460 {
1461         struct ads7846 *ts = spi_get_drvdata(spi);
1462
1463         device_init_wakeup(&spi->dev, false);
1464
1465         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1466
1467         ads7846_disable(ts);
1468         free_irq(ts->spi->irq, ts);
1469
1470         input_unregister_device(ts->input);
1471
1472         ads784x_hwmon_unregister(spi, ts);
1473
1474         regulator_disable(ts->reg);
1475         regulator_put(ts->reg);
1476
1477         if (!ts->get_pendown_state) {
1478                 /*
1479                  * If we are not using specialized pendown method we must
1480                  * have been relying on gpio we set up ourselves.
1481                  */
1482                 gpio_free(ts->gpio_pendown);
1483         }
1484
1485         if (ts->filter_cleanup)
1486                 ts->filter_cleanup(ts->filter_data);
1487
1488         kfree(ts->packet);
1489         kfree(ts);
1490
1491         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1492
1493         return 0;
1494 }
1495
1496 static struct spi_driver ads7846_driver = {
1497         .driver = {
1498                 .name   = "ads7846",
1499                 .pm     = &ads7846_pm,
1500                 .of_match_table = of_match_ptr(ads7846_dt_ids),
1501         },
1502         .probe          = ads7846_probe,
1503         .remove         = ads7846_remove,
1504 };
1505
1506 module_spi_driver(ads7846_driver);
1507
1508 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1509 MODULE_LICENSE("GPL");
1510 MODULE_ALIAS("spi:ads7846");