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         int value;
 672         struct spi_transfer *t =
 673                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 674
 675         if (ts->model == 7845) {
 676                 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
 677         } else {
 678                 /*
 679                  * adjust:  on-wire is a must-ignore bit, a BE12 value, then
 680                  * padding; built from two 8 bit values written msb-first.
 681                  */
 682                 value = be16_to_cpup((__be16 *)t->rx_buf);
 683         }
 684
 685         /* enforce ADC output is 12 bits width */
 686         return (value >> 3) & 0xfff;
 687 }
 688
 689 static void ads7846_update_value(struct spi_message *m, int val)
 690 {
 691         struct spi_transfer *t =
 692                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 693
 694         *(u16 *)t->rx_buf = val;
 695 }
 696
 697 static void ads7846_read_state(struct ads7846 *ts)
 698 {
 699         struct ads7846_packet *packet = ts->packet;
 700         struct spi_message *m;
 701         int msg_idx = 0;
 702         int val;
 703         int action;
 704         int error;
 705
 706         while (msg_idx < ts->msg_count) {
 707
 708                 ts->wait_for_sync();
 709
 710                 m = &ts->msg[msg_idx];
 711                 error = spi_sync(ts->spi, m);
 712                 if (error) {
 713                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 714                         packet->tc.ignore = true;
 715                         return;
 716                 }
 717
 718                 /*
 719                  * Last message is power down request, no need to convert
 720                  * or filter the value.
 721                  */
 722                 if (msg_idx < ts->msg_count - 1) {
 723
 724                         val = ads7846_get_value(ts, m);
 725
 726                         action = ts->filter(ts->filter_data, msg_idx, &val);
 727                         switch (action) {
 728                         case ADS7846_FILTER_REPEAT:
 729                                 continue;
 730
 731                         case ADS7846_FILTER_IGNORE:
 732                                 packet->tc.ignore = true;
 733                                 msg_idx = ts->msg_count - 1;
 734                                 continue;
 735
 736                         case ADS7846_FILTER_OK:
 737                                 ads7846_update_value(m, val);
 738                                 packet->tc.ignore = false;
 739                                 msg_idx++;
 740                                 break;
 741
 742                         default:
 743                                 BUG();
 744                         }
 745                 } else {
 746                         msg_idx++;
 747                 }
 748         }
 749 }
 750
 751 static void ads7846_report_state(struct ads7846 *ts)
 752 {
 753         struct ads7846_packet *packet = ts->packet;
 754         unsigned int Rt;
 755         u16 x, y, z1, z2;
 756
 757         /*
 758          * ads7846_get_value() does in-place conversion (including byte swap)
 759          * from on-the-wire format as part of debouncing to get stable
 760          * readings.
 761          */
 762         if (ts->model == 7845) {
 763                 x = *(u16 *)packet->tc.x_buf;
 764                 y = *(u16 *)packet->tc.y_buf;
 765                 z1 = 0;
 766                 z2 = 0;
 767         } else {
 768                 x = packet->tc.x;
 769                 y = packet->tc.y;
 770                 z1 = packet->tc.z1;
 771                 z2 = packet->tc.z2;
 772         }
 773
 774         /* range filtering */
 775         if (x == MAX_12BIT)
 776                 x = 0;
 777
 778         if (ts->model == 7843) {
 779                 Rt = ts->pressure_max / 2;
 780         } else if (ts->model == 7845) {
 781                 if (get_pendown_state(ts))
 782                         Rt = ts->pressure_max / 2;
 783                 else
 784                         Rt = 0;
 785                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 786         } else if (likely(x && z1)) {
 787                 /* compute touch pressure resistance using equation #2 */
 788                 Rt = z2;
 789                 Rt -= z1;
 790                 Rt *= x;
 791                 Rt *= ts->x_plate_ohms;
 792                 Rt /= z1;
 793                 Rt = (Rt + 2047) >> 12;
 794         } else {
 795                 Rt = 0;
 796         }
 797
 798         /*
 799          * Sample found inconsistent by debouncing or pressure is beyond
 800          * the maximum. Don't report it to user space, repeat at least
 801          * once more the measurement
 802          */
 803         if (packet->tc.ignore || Rt > ts->pressure_max) {
 804                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 805                          packet->tc.ignore, Rt);
 806                 return;
 807         }
 808
 809         /*
 810          * Maybe check the pendown state before reporting. This discards
 811          * false readings when the pen is lifted.
 812          */
 813         if (ts->penirq_recheck_delay_usecs) {
 814                 udelay(ts->penirq_recheck_delay_usecs);
 815                 if (!get_pendown_state(ts))
 816                         Rt = 0;
 817         }
 818
 819         /*
 820          * NOTE: We can't rely on the pressure to determine the pen down
 821          * state, even this controller has a pressure sensor. The pressure
 822          * value can fluctuate for quite a while after lifting the pen and
 823          * in some cases may not even settle at the expected value.
 824          *
 825          * The only safe way to check for the pen up condition is in the
 826          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 827          */
 828         if (Rt) {
 829                 struct input_dev *input = ts->input;
 830
 831                 if (ts->swap_xy)
 832                         swap(x, y);
 833
 834                 if (!ts->pendown) {
 835                         input_report_key(input, BTN_TOUCH, 1);
 836                         ts->pendown = true;
 837                         dev_vdbg(&ts->spi->dev, "DOWN\n");
 838                 }
 839
 840                 input_report_abs(input, ABS_X, x);
 841                 input_report_abs(input, ABS_Y, y);
 842                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 843
 844                 input_sync(input);
 845                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
 846         }
 847 }
 848
 849 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 850 {
 851         struct ads7846 *ts = handle;
 852
 853         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 854 }
 855
 856
 857 static irqreturn_t ads7846_irq(int irq, void *handle)
 858 {
 859         struct ads7846 *ts = handle;
 860
 861         /* Start with a small delay before checking pendown state */
 862         msleep(TS_POLL_DELAY);
 863
 864         while (!ts->stopped && get_pendown_state(ts)) {
 865
 866                 /* pen is down, continue with the measurement */
 867                 ads7846_read_state(ts);
 868
 869                 if (!ts->stopped)
 870                         ads7846_report_state(ts);
 871
 872                 wait_event_timeout(ts->wait, ts->stopped,
 873                                    msecs_to_jiffies(TS_POLL_PERIOD));
 874         }
 875
 876         if (ts->pendown) {
 877                 struct input_dev *input = ts->input;
 878
 879                 input_report_key(input, BTN_TOUCH, 0);
 880                 input_report_abs(input, ABS_PRESSURE, 0);
 881                 input_sync(input);
 882
 883                 ts->pendown = false;
 884                 dev_vdbg(&ts->spi->dev, "UP\n");
 885         }
 886
 887         return IRQ_HANDLED;
 888 }
 889
 890 #ifdef CONFIG_PM_SLEEP
 891 static int ads7846_suspend(struct device *dev)
 892 {
 893         struct ads7846 *ts = dev_get_drvdata(dev);
 894
 895         mutex_lock(&ts->lock);
 896
 897         if (!ts->suspended) {
 898
 899                 if (!ts->disabled)
 900                         __ads7846_disable(ts);
 901
 902                 if (device_may_wakeup(&ts->spi->dev))
 903                         enable_irq_wake(ts->spi->irq);
 904
 905                 ts->suspended = true;
 906         }
 907
 908         mutex_unlock(&ts->lock);
 909
 910         return 0;
 911 }
 912
 913 static int ads7846_resume(struct device *dev)
 914 {
 915         struct ads7846 *ts = dev_get_drvdata(dev);
 916
 917         mutex_lock(&ts->lock);
 918
 919         if (ts->suspended) {
 920
 921                 ts->suspended = false;
 922
 923                 if (device_may_wakeup(&ts->spi->dev))
 924                         disable_irq_wake(ts->spi->irq);
 925
 926                 if (!ts->disabled)
 927                         __ads7846_enable(ts);
 928         }
 929
 930         mutex_unlock(&ts->lock);
 931
 932         return 0;
 933 }
 934 #endif
 935
 936 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 937
 938 static int ads7846_setup_pendown(struct spi_device *spi,
 939                                  struct ads7846 *ts,
 940                                  const struct ads7846_platform_data *pdata)
 941 {
 942         int err;
 943
 944         /*
 945          * REVISIT when the irq can be triggered active-low, or if for some
 946          * reason the touchscreen isn't hooked up, we don't need to access
 947          * the pendown state.
 948          */
 949
 950         if (pdata->get_pendown_state) {
 951                 ts->get_pendown_state = pdata->get_pendown_state;
 952         } else if (gpio_is_valid(pdata->gpio_pendown)) {
 953
 954                 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
 955                                        "ads7846_pendown");
 956                 if (err) {
 957                         dev_err(&spi->dev,
 958                                 "failed to request/setup pendown GPIO%d: %d\n",
 959                                 pdata->gpio_pendown, err);
 960                         return err;
 961                 }
 962
 963                 ts->gpio_pendown = pdata->gpio_pendown;
 964
 965                 if (pdata->gpio_pendown_debounce)
 966                         gpio_set_debounce(pdata->gpio_pendown,
 967                                           pdata->gpio_pendown_debounce);
 968         } else {
 969                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 970                 return -EINVAL;
 971         }
 972
 973         return 0;
 974 }
 975
 976 /*
 977  * Set up the transfers to read touchscreen state; this assumes we
 978  * use formula #2 for pressure, not #3.
 979  */
 980 static void ads7846_setup_spi_msg(struct ads7846 *ts,
 981                                   const struct ads7846_platform_data *pdata)
 982 {
 983         struct spi_message *m = &ts->msg[0];
 984         struct spi_transfer *x = ts->xfer;
 985         struct ads7846_packet *packet = ts->packet;
 986         int vref = pdata->keep_vref_on;
 987
 988         if (ts->model == 7873) {
 989                 /*
 990                  * The AD7873 is almost identical to the ADS7846
 991                  * keep VREF off during differential/ratiometric
 992                  * conversion modes.
 993                  */
 994                 ts->model = 7846;
 995                 vref = 0;
 996         }
 997
 998         ts->msg_count = 1;
 999         spi_message_init(m);
1000         m->context = ts;
1001
1002         if (ts->model == 7845) {
1003                 packet->read_y_cmd[0] = READ_Y(vref);
1004                 packet->read_y_cmd[1] = 0;
1005                 packet->read_y_cmd[2] = 0;
1006                 x->tx_buf = &packet->read_y_cmd[0];
1007                 x->rx_buf = &packet->tc.y_buf[0];
1008                 x->len = 3;
1009                 spi_message_add_tail(x, m);
1010         } else {
1011                 /* y- still on; turn on only y+ (and ADC) */
1012                 packet->read_y = READ_Y(vref);
1013                 x->tx_buf = &packet->read_y;
1014                 x->len = 1;
1015                 spi_message_add_tail(x, m);
1016
1017                 x++;
1018                 x->rx_buf = &packet->tc.y;
1019                 x->len = 2;
1020                 spi_message_add_tail(x, m);
1021         }
1022
1023         /*
1024          * The first sample after switching drivers can be low quality;
1025          * optionally discard it, using a second one after the signals
1026          * have had enough time to stabilize.
1027          */
1028         if (pdata->settle_delay_usecs) {
1029                 x->delay_usecs = pdata->settle_delay_usecs;
1030
1031                 x++;
1032                 x->tx_buf = &packet->read_y;
1033                 x->len = 1;
1034                 spi_message_add_tail(x, m);
1035
1036                 x++;
1037                 x->rx_buf = &packet->tc.y;
1038                 x->len = 2;
1039                 spi_message_add_tail(x, m);
1040         }
1041
1042         ts->msg_count++;
1043         m++;
1044         spi_message_init(m);
1045         m->context = ts;
1046
1047         if (ts->model == 7845) {
1048                 x++;
1049                 packet->read_x_cmd[0] = READ_X(vref);
1050                 packet->read_x_cmd[1] = 0;
1051                 packet->read_x_cmd[2] = 0;
1052                 x->tx_buf = &packet->read_x_cmd[0];
1053                 x->rx_buf = &packet->tc.x_buf[0];
1054                 x->len = 3;
1055                 spi_message_add_tail(x, m);
1056         } else {
1057                 /* turn y- off, x+ on, then leave in lowpower */
1058                 x++;
1059                 packet->read_x = READ_X(vref);
1060                 x->tx_buf = &packet->read_x;
1061                 x->len = 1;
1062                 spi_message_add_tail(x, m);
1063
1064                 x++;
1065                 x->rx_buf = &packet->tc.x;
1066                 x->len = 2;
1067                 spi_message_add_tail(x, m);
1068         }
1069
1070         /* ... maybe discard first sample ... */
1071         if (pdata->settle_delay_usecs) {
1072                 x->delay_usecs = pdata->settle_delay_usecs;
1073
1074                 x++;
1075                 x->tx_buf = &packet->read_x;
1076                 x->len = 1;
1077                 spi_message_add_tail(x, m);
1078
1079                 x++;
1080                 x->rx_buf = &packet->tc.x;
1081                 x->len = 2;
1082                 spi_message_add_tail(x, m);
1083         }
1084
1085         /* turn y+ off, x- on; we'll use formula #2 */
1086         if (ts->model == 7846) {
1087                 ts->msg_count++;
1088                 m++;
1089                 spi_message_init(m);
1090                 m->context = ts;
1091
1092                 x++;
1093                 packet->read_z1 = READ_Z1(vref);
1094                 x->tx_buf = &packet->read_z1;
1095                 x->len = 1;
1096                 spi_message_add_tail(x, m);
1097
1098                 x++;
1099                 x->rx_buf = &packet->tc.z1;
1100                 x->len = 2;
1101                 spi_message_add_tail(x, m);
1102
1103                 /* ... maybe discard first sample ... */
1104                 if (pdata->settle_delay_usecs) {
1105                         x->delay_usecs = pdata->settle_delay_usecs;
1106
1107                         x++;
1108                         x->tx_buf = &packet->read_z1;
1109                         x->len = 1;
1110                         spi_message_add_tail(x, m);
1111
1112                         x++;
1113                         x->rx_buf = &packet->tc.z1;
1114                         x->len = 2;
1115                         spi_message_add_tail(x, m);
1116                 }
1117
1118                 ts->msg_count++;
1119                 m++;
1120                 spi_message_init(m);
1121                 m->context = ts;
1122
1123                 x++;
1124                 packet->read_z2 = READ_Z2(vref);
1125                 x->tx_buf = &packet->read_z2;
1126                 x->len = 1;
1127                 spi_message_add_tail(x, m);
1128
1129                 x++;
1130                 x->rx_buf = &packet->tc.z2;
1131                 x->len = 2;
1132                 spi_message_add_tail(x, m);
1133
1134                 /* ... maybe discard first sample ... */
1135                 if (pdata->settle_delay_usecs) {
1136                         x->delay_usecs = pdata->settle_delay_usecs;
1137
1138                         x++;
1139                         x->tx_buf = &packet->read_z2;
1140                         x->len = 1;
1141                         spi_message_add_tail(x, m);
1142
1143                         x++;
1144                         x->rx_buf = &packet->tc.z2;
1145                         x->len = 2;
1146                         spi_message_add_tail(x, m);
1147                 }
1148         }
1149
1150         /* power down */
1151         ts->msg_count++;
1152         m++;
1153         spi_message_init(m);
1154         m->context = ts;
1155
1156         if (ts->model == 7845) {
1157                 x++;
1158                 packet->pwrdown_cmd[0] = PWRDOWN;
1159                 packet->pwrdown_cmd[1] = 0;
1160                 packet->pwrdown_cmd[2] = 0;
1161                 x->tx_buf = &packet->pwrdown_cmd[0];
1162                 x->len = 3;
1163         } else {
1164                 x++;
1165                 packet->pwrdown = PWRDOWN;
1166                 x->tx_buf = &packet->pwrdown;
1167                 x->len = 1;
1168                 spi_message_add_tail(x, m);
1169
1170                 x++;
1171                 x->rx_buf = &packet->dummy;
1172                 x->len = 2;
1173         }
1174
1175         CS_CHANGE(*x);
1176         spi_message_add_tail(x, m);
1177 }
1178
1179 #ifdef CONFIG_OF
1180 static const struct of_device_id ads7846_dt_ids[] = {
1181         { .compatible = "ti,tsc2046",   .data = (void *) 7846 },
1182         { .compatible = "ti,ads7843",   .data = (void *) 7843 },
1183         { .compatible = "ti,ads7845",   .data = (void *) 7845 },
1184         { .compatible = "ti,ads7846",   .data = (void *) 7846 },
1185         { .compatible = "ti,ads7873",   .data = (void *) 7873 },
1186         { }
1187 };
1188 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1189
1190 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1191 {
1192         struct ads7846_platform_data *pdata;
1193         struct device_node *node = dev->of_node;
1194         const struct of_device_id *match;
1195
1196         if (!node) {
1197                 dev_err(dev, "Device does not have associated DT data\n");
1198                 return ERR_PTR(-EINVAL);
1199         }
1200
1201         match = of_match_device(ads7846_dt_ids, dev);
1202         if (!match) {
1203                 dev_err(dev, "Unknown device model\n");
1204                 return ERR_PTR(-EINVAL);
1205         }
1206
1207         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1208         if (!pdata)
1209                 return ERR_PTR(-ENOMEM);
1210
1211         pdata->model = (unsigned long)match->data;
1212
1213         of_property_read_u16(node, "ti,vref-delay-usecs",
1214                              &pdata->vref_delay_usecs);
1215         of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1216         pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1217
1218         pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1219
1220         of_property_read_u16(node, "ti,settle-delay-usec",
1221                              &pdata->settle_delay_usecs);
1222         of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1223                              &pdata->penirq_recheck_delay_usecs);
1224
1225         of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1226         of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1227
1228         of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1229         of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1230         of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1231         of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1232
1233         of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1234         of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1235
1236         of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1237         of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1238         of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1239
1240         of_property_read_u32(node, "ti,pendown-gpio-debounce",
1241                              &pdata->gpio_pendown_debounce);
1242
1243         pdata->wakeup = of_property_read_bool(node, "linux,wakeup");
1244
1245         pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1246
1247         return pdata;
1248 }
1249 #else
1250 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1251 {
1252         dev_err(dev, "no platform data defined\n");
1253         return ERR_PTR(-EINVAL);
1254 }
1255 #endif
1256
1257 static int ads7846_probe(struct spi_device *spi)
1258 {
1259         const struct ads7846_platform_data *pdata;
1260         struct ads7846 *ts;
1261         struct ads7846_packet *packet;
1262         struct input_dev *input_dev;
1263         unsigned long irq_flags;
1264         int err;
1265
1266         if (!spi->irq) {
1267                 dev_dbg(&spi->dev, "no IRQ?\n");
1268                 return -EINVAL;
1269         }
1270
1271         /* don't exceed max specified sample rate */
1272         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1273                 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1274                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1275                 return -EINVAL;
1276         }
1277
1278         /*
1279          * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1280          * that even if the hardware can do that, the SPI controller driver
1281          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1282          */
1283         spi->bits_per_word = 8;
1284         spi->mode = SPI_MODE_0;
1285         err = spi_setup(spi);
1286         if (err < 0)
1287                 return err;
1288
1289         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1290         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1291         input_dev = input_allocate_device();
1292         if (!ts || !packet || !input_dev) {
1293                 err = -ENOMEM;
1294                 goto err_free_mem;
1295         }
1296
1297         spi_set_drvdata(spi, ts);
1298
1299         ts->packet = packet;
1300         ts->spi = spi;
1301         ts->input = input_dev;
1302
1303         mutex_init(&ts->lock);
1304         init_waitqueue_head(&ts->wait);
1305
1306         pdata = dev_get_platdata(&spi->dev);
1307         if (!pdata) {
1308                 pdata = ads7846_probe_dt(&spi->dev);
1309                 if (IS_ERR(pdata))
1310                         return PTR_ERR(pdata);
1311         }
1312
1313         ts->model = pdata->model ? : 7846;
1314         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1315         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1316         ts->pressure_max = pdata->pressure_max ? : ~0;
1317
1318         ts->vref_mv = pdata->vref_mv;
1319         ts->swap_xy = pdata->swap_xy;
1320
1321         if (pdata->filter != NULL) {
1322                 if (pdata->filter_init != NULL) {
1323                         err = pdata->filter_init(pdata, &ts->filter_data);
1324                         if (err < 0)
1325                                 goto err_free_mem;
1326                 }
1327                 ts->filter = pdata->filter;
1328                 ts->filter_cleanup = pdata->filter_cleanup;
1329         } else if (pdata->debounce_max) {
1330                 ts->debounce_max = pdata->debounce_max;
1331                 if (ts->debounce_max < 2)
1332                         ts->debounce_max = 2;
1333                 ts->debounce_tol = pdata->debounce_tol;
1334                 ts->debounce_rep = pdata->debounce_rep;
1335                 ts->filter = ads7846_debounce_filter;
1336                 ts->filter_data = ts;
1337         } else {
1338                 ts->filter = ads7846_no_filter;
1339         }
1340
1341         err = ads7846_setup_pendown(spi, ts, pdata);
1342         if (err)
1343                 goto err_cleanup_filter;
1344
1345         if (pdata->penirq_recheck_delay_usecs)
1346                 ts->penirq_recheck_delay_usecs =
1347                                 pdata->penirq_recheck_delay_usecs;
1348
1349         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1350
1351         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1352         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1353
1354         input_dev->name = ts->name;
1355         input_dev->phys = ts->phys;
1356         input_dev->dev.parent = &spi->dev;
1357
1358         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1359         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1360         input_set_abs_params(input_dev, ABS_X,
1361                         pdata->x_min ? : 0,
1362                         pdata->x_max ? : MAX_12BIT,
1363                         0, 0);
1364         input_set_abs_params(input_dev, ABS_Y,
1365                         pdata->y_min ? : 0,
1366                         pdata->y_max ? : MAX_12BIT,
1367                         0, 0);
1368         input_set_abs_params(input_dev, ABS_PRESSURE,
1369                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1370
1371         ads7846_setup_spi_msg(ts, pdata);
1372
1373         ts->reg = regulator_get(&spi->dev, "vcc");
1374         if (IS_ERR(ts->reg)) {
1375                 err = PTR_ERR(ts->reg);
1376                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1377                 goto err_free_gpio;
1378         }
1379
1380         err = regulator_enable(ts->reg);
1381         if (err) {
1382                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1383                 goto err_put_regulator;
1384         }
1385
1386         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1387         irq_flags |= IRQF_ONESHOT;
1388
1389         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1390                                    irq_flags, spi->dev.driver->name, ts);
1391         if (err && !pdata->irq_flags) {
1392                 dev_info(&spi->dev,
1393                         "trying pin change workaround on irq %d\n", spi->irq);
1394                 irq_flags |= IRQF_TRIGGER_RISING;
1395                 err = request_threaded_irq(spi->irq,
1396                                   ads7846_hard_irq, ads7846_irq,
1397                                   irq_flags, spi->dev.driver->name, ts);
1398         }
1399
1400         if (err) {
1401                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1402                 goto err_disable_regulator;
1403         }
1404
1405         err = ads784x_hwmon_register(spi, ts);
1406         if (err)
1407                 goto err_free_irq;
1408
1409         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1410
1411         /*
1412          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1413          * the touchscreen, in case it's not connected.
1414          */
1415         if (ts->model == 7845)
1416                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1417         else
1418                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1419
1420         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1421         if (err)
1422                 goto err_remove_hwmon;
1423
1424         err = input_register_device(input_dev);
1425         if (err)
1426                 goto err_remove_attr_group;
1427
1428         device_init_wakeup(&spi->dev, pdata->wakeup);
1429
1430         /*
1431          * If device does not carry platform data we must have allocated it
1432          * when parsing DT data.
1433          */
1434         if (!dev_get_platdata(&spi->dev))
1435                 devm_kfree(&spi->dev, (void *)pdata);
1436
1437         return 0;
1438
1439  err_remove_attr_group:
1440         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1441  err_remove_hwmon:
1442         ads784x_hwmon_unregister(spi, ts);
1443  err_free_irq:
1444         free_irq(spi->irq, ts);
1445  err_disable_regulator:
1446         regulator_disable(ts->reg);
1447  err_put_regulator:
1448         regulator_put(ts->reg);
1449  err_free_gpio:
1450         if (!ts->get_pendown_state)
1451                 gpio_free(ts->gpio_pendown);
1452  err_cleanup_filter:
1453         if (ts->filter_cleanup)
1454                 ts->filter_cleanup(ts->filter_data);
1455  err_free_mem:
1456         input_free_device(input_dev);
1457         kfree(packet);
1458         kfree(ts);
1459         return err;
1460 }
1461
1462 static int ads7846_remove(struct spi_device *spi)
1463 {
1464         struct ads7846 *ts = spi_get_drvdata(spi);
1465
1466         device_init_wakeup(&spi->dev, false);
1467
1468         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1469
1470         ads7846_disable(ts);
1471         free_irq(ts->spi->irq, ts);
1472
1473         input_unregister_device(ts->input);
1474
1475         ads784x_hwmon_unregister(spi, ts);
1476
1477         regulator_disable(ts->reg);
1478         regulator_put(ts->reg);
1479
1480         if (!ts->get_pendown_state) {
1481                 /*
1482                  * If we are not using specialized pendown method we must
1483                  * have been relying on gpio we set up ourselves.
1484                  */
1485                 gpio_free(ts->gpio_pendown);
1486         }
1487
1488         if (ts->filter_cleanup)
1489                 ts->filter_cleanup(ts->filter_data);
1490
1491         kfree(ts->packet);
1492         kfree(ts);
1493
1494         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1495
1496         return 0;
1497 }
1498
1499 static struct spi_driver ads7846_driver = {
1500         .driver = {
1501                 .name   = "ads7846",
1502                 .owner  = THIS_MODULE,
1503                 .pm     = &ads7846_pm,
1504                 .of_match_table = of_match_ptr(ads7846_dt_ids),
1505         },
1506         .probe          = ads7846_probe,
1507         .remove         = ads7846_remove,
1508 };
1509
1510 module_spi_driver(ads7846_driver);
1511
1512 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1513 MODULE_LICENSE("GPL");
1514 MODULE_ALIAS("spi:ads7846");