drivers/input/touchscreen/ads7846.c

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This source file includes following definitions.
ads7846_stop
ads7846_restart
__ads7846_disable
__ads7846_enable
ads7846_disable
ads7846_enable
ads7846_read12_ser
ads7845_read12_ser
null_adjust
SHOW
vbatt_adjust
SHOW
ads784x_hwmon_register
ads784x_hwmon_unregister
ads784x_hwmon_register
ads784x_hwmon_unregister
ads7846_pen_down_show
ads7846_disable_show
ads7846_disable_store
get_pendown_state
null_wait_for_sync
ads7846_debounce_filter
ads7846_no_filter
ads7846_get_value
ads7846_update_value
ads7846_read_state
ads7846_report_state
ads7846_hard_irq
ads7846_irq
ads7846_suspend
ads7846_resume
ads7846_setup_pendown
ads7846_setup_spi_msg
ads7846_probe_dt
ads7846_probe_dt
ads7846_probe
ads7846_remove
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ADS7846 based touchscreen and sensor driver
   4  *
   5  * Copyright (c) 2005 David Brownell
   6  * Copyright (c) 2006 Nokia Corporation
   7  * Various changes: Imre Deak <imre.deak@nokia.com>
   8  *
   9  * Using code from:
  10  *  - corgi_ts.c
  11  *      Copyright (C) 2004-2005 Richard Purdie
  12  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  13  *      Copyright (C) 2002 MontaVista Software
  14  *      Copyright (C) 2004 Texas Instruments
  15  *      Copyright (C) 2005 Dirk Behme
  16  */
  17 #include <linux/types.h>
  18 #include <linux/hwmon.h>
  19 #include <linux/err.h>
  20 #include <linux/sched.h>
  21 #include <linux/delay.h>
  22 #include <linux/input.h>
  23 #include <linux/input/touchscreen.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/slab.h>
  26 #include <linux/pm.h>
  27 #include <linux/of.h>
  28 #include <linux/of_gpio.h>
  29 #include <linux/of_device.h>
  30 #include <linux/gpio.h>
  31 #include <linux/spi/spi.h>
  32 #include <linux/spi/ads7846.h>
  33 #include <linux/regulator/consumer.h>
  34 #include <linux/module.h>
  35 #include <asm/irq.h>
  36 
  37 /*
  38  * This code has been heavily tested on a Nokia 770, and lightly
  39  * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
  40  * TSC2046 is just newer ads7846 silicon.
  41  * Support for ads7843 tested on Atmel at91sam926x-EK.
  42  * Support for ads7845 has only been stubbed in.
  43  * Support for Analog Devices AD7873 and AD7843 tested.
  44  *
  45  * IRQ handling needs a workaround because of a shortcoming in handling
  46  * edge triggered IRQs on some platforms like the OMAP1/2. These
  47  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
  48  * have to maintain our own SW IRQ disabled status. This should be
  49  * removed as soon as the affected platform's IRQ handling is fixed.
  50  *
  51  * App note sbaa036 talks in more detail about accurate sampling...
  52  * that ought to help in situations like LCDs inducing noise (which
  53  * can also be helped by using synch signals) and more generally.
  54  * This driver tries to utilize the measures described in the app
  55  * note. The strength of filtering can be set in the board-* specific
  56  * files.
  57  */
  58 
  59 #define TS_POLL_DELAY   1       /* ms delay before the first sample */
  60 #define TS_POLL_PERIOD  5       /* ms delay between samples */
  61 
  62 /* this driver doesn't aim at the peak continuous sample rate */
  63 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
  64 
  65 struct ts_event {
  66         /*
  67          * For portability, we can't read 12 bit values using SPI (which
  68          * would make the controller deliver them as native byte order u16
  69          * with msbs zeroed).  Instead, we read them as two 8-bit values,
  70          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
  71          */
  72         u16     x;
  73         u16     y;
  74         u16     z1, z2;
  75         bool    ignore;
  76         u8      x_buf[3];
  77         u8      y_buf[3];
  78 };
  79 
  80 /*
  81  * We allocate this separately to avoid cache line sharing issues when
  82  * driver is used with DMA-based SPI controllers (like atmel_spi) on
  83  * systems where main memory is not DMA-coherent (most non-x86 boards).
  84  */
  85 struct ads7846_packet {
  86         u8                      read_x, read_y, read_z1, read_z2, pwrdown;
  87         u16                     dummy;          /* for the pwrdown read */
  88         struct ts_event         tc;
  89         /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
  90         u8                      read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
  91 };
  92 
  93 struct ads7846 {
  94         struct input_dev        *input;
  95         char                    phys[32];
  96         char                    name[32];
  97 
  98         struct spi_device       *spi;
  99         struct regulator        *reg;
 100 
 101 #if IS_ENABLED(CONFIG_HWMON)
 102         struct device           *hwmon;
 103 #endif
 104 
 105         u16                     model;
 106         u16                     vref_mv;
 107         u16                     vref_delay_usecs;
 108         u16                     x_plate_ohms;
 109         u16                     pressure_max;
 110 
 111         bool                    swap_xy;
 112         bool                    use_internal;
 113 
 114         struct ads7846_packet   *packet;
 115 
 116         struct spi_transfer     xfer[18];
 117         struct spi_message      msg[5];
 118         int                     msg_count;
 119         wait_queue_head_t       wait;
 120 
 121         bool                    pendown;
 122 
 123         int                     read_cnt;
 124         int                     read_rep;
 125         int                     last_read;
 126 
 127         u16                     debounce_max;
 128         u16                     debounce_tol;
 129         u16                     debounce_rep;
 130 
 131         u16                     penirq_recheck_delay_usecs;
 132 
 133         struct touchscreen_properties core_prop;
 134 
 135         struct mutex            lock;
 136         bool                    stopped;        /* P: lock */
 137         bool                    disabled;       /* P: lock */
 138         bool                    suspended;      /* P: lock */
 139 
 140         int                     (*filter)(void *data, int data_idx, int *val);
 141         void                    *filter_data;
 142         void                    (*filter_cleanup)(void *data);
 143         int                     (*get_pendown_state)(void);
 144         int                     gpio_pendown;
 145 
 146         void                    (*wait_for_sync)(void);
 147 };
 148 
 149 /* leave chip selected when we're done, for quicker re-select? */
 150 #if     0
 151 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
 152 #else
 153 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
 154 #endif
 155 
 156 /*--------------------------------------------------------------------------*/
 157 
 158 /* The ADS7846 has touchscreen and other sensors.
 159  * Earlier ads784x chips are somewhat compatible.
 160  */
 161 #define ADS_START               (1 << 7)
 162 #define ADS_A2A1A0_d_y          (1 << 4)        /* differential */
 163 #define ADS_A2A1A0_d_z1         (3 << 4)        /* differential */
 164 #define ADS_A2A1A0_d_z2         (4 << 4)        /* differential */
 165 #define ADS_A2A1A0_d_x          (5 << 4)        /* differential */
 166 #define ADS_A2A1A0_temp0        (0 << 4)        /* non-differential */
 167 #define ADS_A2A1A0_vbatt        (2 << 4)        /* non-differential */
 168 #define ADS_A2A1A0_vaux         (6 << 4)        /* non-differential */
 169 #define ADS_A2A1A0_temp1        (7 << 4)        /* non-differential */
 170 #define ADS_8_BIT               (1 << 3)
 171 #define ADS_12_BIT              (0 << 3)
 172 #define ADS_SER                 (1 << 2)        /* non-differential */
 173 #define ADS_DFR                 (0 << 2)        /* differential */
 174 #define ADS_PD10_PDOWN          (0 << 0)        /* low power mode + penirq */
 175 #define ADS_PD10_ADC_ON         (1 << 0)        /* ADC on */
 176 #define ADS_PD10_REF_ON         (2 << 0)        /* vREF on + penirq */
 177 #define ADS_PD10_ALL_ON         (3 << 0)        /* ADC + vREF on */
 178 
 179 #define MAX_12BIT       ((1<<12)-1)
 180 
 181 /* leave ADC powered up (disables penirq) between differential samples */
 182 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
 183         | ADS_12_BIT | ADS_DFR | \
 184         (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
 185 
 186 #define READ_Y(vref)    (READ_12BIT_DFR(y,  1, vref))
 187 #define READ_Z1(vref)   (READ_12BIT_DFR(z1, 1, vref))
 188 #define READ_Z2(vref)   (READ_12BIT_DFR(z2, 1, vref))
 189 
 190 #define READ_X(vref)    (READ_12BIT_DFR(x,  1, vref))
 191 #define PWRDOWN         (READ_12BIT_DFR(y,  0, 0))      /* LAST */
 192 
 193 /* single-ended samples need to first power up reference voltage;
 194  * we leave both ADC and VREF powered
 195  */
 196 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
 197         | ADS_12_BIT | ADS_SER)
 198 
 199 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
 200 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 201 
 202 /* Must be called with ts->lock held */
 203 static void ads7846_stop(struct ads7846 *ts)
 204 {
 205         if (!ts->disabled && !ts->suspended) {
 206                 /* Signal IRQ thread to stop polling and disable the handler. */
 207                 ts->stopped = true;
 208                 mb();
 209                 wake_up(&ts->wait);
 210                 disable_irq(ts->spi->irq);
 211         }
 212 }
 213 
 214 /* Must be called with ts->lock held */
 215 static void ads7846_restart(struct ads7846 *ts)
 216 {
 217         if (!ts->disabled && !ts->suspended) {
 218                 /* Tell IRQ thread that it may poll the device. */
 219                 ts->stopped = false;
 220                 mb();
 221                 enable_irq(ts->spi->irq);
 222         }
 223 }
 224 
 225 /* Must be called with ts->lock held */
 226 static void __ads7846_disable(struct ads7846 *ts)
 227 {
 228         ads7846_stop(ts);
 229         regulator_disable(ts->reg);
 230 
 231         /*
 232          * We know the chip's in low power mode since we always
 233          * leave it that way after every request
 234          */
 235 }
 236 
 237 /* Must be called with ts->lock held */
 238 static void __ads7846_enable(struct ads7846 *ts)
 239 {
 240         int error;
 241 
 242         error = regulator_enable(ts->reg);
 243         if (error != 0)
 244                 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
 245 
 246         ads7846_restart(ts);
 247 }
 248 
 249 static void ads7846_disable(struct ads7846 *ts)
 250 {
 251         mutex_lock(&ts->lock);
 252 
 253         if (!ts->disabled) {
 254 
 255                 if  (!ts->suspended)
 256                         __ads7846_disable(ts);
 257 
 258                 ts->disabled = true;
 259         }
 260 
 261         mutex_unlock(&ts->lock);
 262 }
 263 
 264 static void ads7846_enable(struct ads7846 *ts)
 265 {
 266         mutex_lock(&ts->lock);
 267 
 268         if (ts->disabled) {
 269 
 270                 ts->disabled = false;
 271 
 272                 if (!ts->suspended)
 273                         __ads7846_enable(ts);
 274         }
 275 
 276         mutex_unlock(&ts->lock);
 277 }
 278 
 279 /*--------------------------------------------------------------------------*/
 280 
 281 /*
 282  * Non-touchscreen sensors only use single-ended conversions.
 283  * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
 284  * ads7846 lets that pin be unconnected, to use internal vREF.
 285  */
 286 
 287 struct ser_req {
 288         u8                      ref_on;
 289         u8                      command;
 290         u8                      ref_off;
 291         u16                     scratch;
 292         struct spi_message      msg;
 293         struct spi_transfer     xfer[6];
 294         /*
 295          * DMA (thus cache coherency maintenance) requires the
 296          * transfer buffers to live in their own cache lines.
 297          */
 298         __be16 sample ____cacheline_aligned;
 299 };
 300 
 301 struct ads7845_ser_req {
 302         u8                      command[3];
 303         struct spi_message      msg;
 304         struct spi_transfer     xfer[2];
 305         /*
 306          * DMA (thus cache coherency maintenance) requires the
 307          * transfer buffers to live in their own cache lines.
 308          */
 309         u8 sample[3] ____cacheline_aligned;
 310 };
 311 
 312 static int ads7846_read12_ser(struct device *dev, unsigned command)
 313 {
 314         struct spi_device *spi = to_spi_device(dev);
 315         struct ads7846 *ts = dev_get_drvdata(dev);
 316         struct ser_req *req;
 317         int status;
 318 
 319         req = kzalloc(sizeof *req, GFP_KERNEL);
 320         if (!req)
 321                 return -ENOMEM;
 322 
 323         spi_message_init(&req->msg);
 324 
 325         /* maybe turn on internal vREF, and let it settle */
 326         if (ts->use_internal) {
 327                 req->ref_on = REF_ON;
 328                 req->xfer[0].tx_buf = &req->ref_on;
 329                 req->xfer[0].len = 1;
 330                 spi_message_add_tail(&req->xfer[0], &req->msg);
 331 
 332                 req->xfer[1].rx_buf = &req->scratch;
 333                 req->xfer[1].len = 2;
 334 
 335                 /* for 1uF, settle for 800 usec; no cap, 100 usec.  */
 336                 req->xfer[1].delay_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 const 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 
 533         return PTR_ERR_OR_ZERO(ts->hwmon);
 534 }
 535 
 536 static void ads784x_hwmon_unregister(struct spi_device *spi,
 537                                      struct ads7846 *ts)
 538 {
 539         if (ts->hwmon)
 540                 hwmon_device_unregister(ts->hwmon);
 541 }
 542 
 543 #else
 544 static inline int ads784x_hwmon_register(struct spi_device *spi,
 545                                          struct ads7846 *ts)
 546 {
 547         return 0;
 548 }
 549 
 550 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
 551                                             struct ads7846 *ts)
 552 {
 553 }
 554 #endif
 555 
 556 static ssize_t ads7846_pen_down_show(struct device *dev,
 557                                      struct device_attribute *attr, char *buf)
 558 {
 559         struct ads7846 *ts = dev_get_drvdata(dev);
 560 
 561         return sprintf(buf, "%u\n", ts->pendown);
 562 }
 563 
 564 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
 565 
 566 static ssize_t ads7846_disable_show(struct device *dev,
 567                                      struct device_attribute *attr, char *buf)
 568 {
 569         struct ads7846 *ts = dev_get_drvdata(dev);
 570 
 571         return sprintf(buf, "%u\n", ts->disabled);
 572 }
 573 
 574 static ssize_t ads7846_disable_store(struct device *dev,
 575                                      struct device_attribute *attr,
 576                                      const char *buf, size_t count)
 577 {
 578         struct ads7846 *ts = dev_get_drvdata(dev);
 579         unsigned int i;
 580         int err;
 581 
 582         err = kstrtouint(buf, 10, &i);
 583         if (err)
 584                 return err;
 585 
 586         if (i)
 587                 ads7846_disable(ts);
 588         else
 589                 ads7846_enable(ts);
 590 
 591         return count;
 592 }
 593 
 594 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 595 
 596 static struct attribute *ads784x_attributes[] = {
 597         &dev_attr_pen_down.attr,
 598         &dev_attr_disable.attr,
 599         NULL,
 600 };
 601 
 602 static const struct attribute_group ads784x_attr_group = {
 603         .attrs = ads784x_attributes,
 604 };
 605 
 606 /*--------------------------------------------------------------------------*/
 607 
 608 static int get_pendown_state(struct ads7846 *ts)
 609 {
 610         if (ts->get_pendown_state)
 611                 return ts->get_pendown_state();
 612 
 613         return !gpio_get_value(ts->gpio_pendown);
 614 }
 615 
 616 static void null_wait_for_sync(void)
 617 {
 618 }
 619 
 620 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
 621 {
 622         struct ads7846 *ts = ads;
 623 
 624         if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 625                 /* Start over collecting consistent readings. */
 626                 ts->read_rep = 0;
 627                 /*
 628                  * Repeat it, if this was the first read or the read
 629                  * wasn't consistent enough.
 630                  */
 631                 if (ts->read_cnt < ts->debounce_max) {
 632                         ts->last_read = *val;
 633                         ts->read_cnt++;
 634                         return ADS7846_FILTER_REPEAT;
 635                 } else {
 636                         /*
 637                          * Maximum number of debouncing reached and still
 638                          * not enough number of consistent readings. Abort
 639                          * the whole sample, repeat it in the next sampling
 640                          * period.
 641                          */
 642                         ts->read_cnt = 0;
 643                         return ADS7846_FILTER_IGNORE;
 644                 }
 645         } else {
 646                 if (++ts->read_rep > ts->debounce_rep) {
 647                         /*
 648                          * Got a good reading for this coordinate,
 649                          * go for the next one.
 650                          */
 651                         ts->read_cnt = 0;
 652                         ts->read_rep = 0;
 653                         return ADS7846_FILTER_OK;
 654                 } else {
 655                         /* Read more values that are consistent. */
 656                         ts->read_cnt++;
 657                         return ADS7846_FILTER_REPEAT;
 658                 }
 659         }
 660 }
 661 
 662 static int ads7846_no_filter(void *ads, int data_idx, int *val)
 663 {
 664         return ADS7846_FILTER_OK;
 665 }
 666 
 667 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
 668 {
 669         int value;
 670         struct spi_transfer *t =
 671                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 672 
 673         if (ts->model == 7845) {
 674                 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
 675         } else {
 676                 /*
 677                  * adjust:  on-wire is a must-ignore bit, a BE12 value, then
 678                  * padding; built from two 8 bit values written msb-first.
 679                  */
 680                 value = be16_to_cpup((__be16 *)t->rx_buf);
 681         }
 682 
 683         /* enforce ADC output is 12 bits width */
 684         return (value >> 3) & 0xfff;
 685 }
 686 
 687 static void ads7846_update_value(struct spi_message *m, int val)
 688 {
 689         struct spi_transfer *t =
 690                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 691 
 692         *(u16 *)t->rx_buf = val;
 693 }
 694 
 695 static void ads7846_read_state(struct ads7846 *ts)
 696 {
 697         struct ads7846_packet *packet = ts->packet;
 698         struct spi_message *m;
 699         int msg_idx = 0;
 700         int val;
 701         int action;
 702         int error;
 703 
 704         while (msg_idx < ts->msg_count) {
 705 
 706                 ts->wait_for_sync();
 707 
 708                 m = &ts->msg[msg_idx];
 709                 error = spi_sync(ts->spi, m);
 710                 if (error) {
 711                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
 712                         packet->tc.ignore = true;
 713                         return;
 714                 }
 715 
 716                 /*
 717                  * Last message is power down request, no need to convert
 718                  * or filter the value.
 719                  */
 720                 if (msg_idx < ts->msg_count - 1) {
 721 
 722                         val = ads7846_get_value(ts, m);
 723 
 724                         action = ts->filter(ts->filter_data, msg_idx, &val);
 725                         switch (action) {
 726                         case ADS7846_FILTER_REPEAT:
 727                                 continue;
 728 
 729                         case ADS7846_FILTER_IGNORE:
 730                                 packet->tc.ignore = true;
 731                                 msg_idx = ts->msg_count - 1;
 732                                 continue;
 733 
 734                         case ADS7846_FILTER_OK:
 735                                 ads7846_update_value(m, val);
 736                                 packet->tc.ignore = false;
 737                                 msg_idx++;
 738                                 break;
 739 
 740                         default:
 741                                 BUG();
 742                         }
 743                 } else {
 744                         msg_idx++;
 745                 }
 746         }
 747 }
 748 
 749 static void ads7846_report_state(struct ads7846 *ts)
 750 {
 751         struct ads7846_packet *packet = ts->packet;
 752         unsigned int Rt;
 753         u16 x, y, z1, z2;
 754 
 755         /*
 756          * ads7846_get_value() does in-place conversion (including byte swap)
 757          * from on-the-wire format as part of debouncing to get stable
 758          * readings.
 759          */
 760         if (ts->model == 7845) {
 761                 x = *(u16 *)packet->tc.x_buf;
 762                 y = *(u16 *)packet->tc.y_buf;
 763                 z1 = 0;
 764                 z2 = 0;
 765         } else {
 766                 x = packet->tc.x;
 767                 y = packet->tc.y;
 768                 z1 = packet->tc.z1;
 769                 z2 = packet->tc.z2;
 770         }
 771 
 772         /* range filtering */
 773         if (x == MAX_12BIT)
 774                 x = 0;
 775 
 776         if (ts->model == 7843) {
 777                 Rt = ts->pressure_max / 2;
 778         } else if (ts->model == 7845) {
 779                 if (get_pendown_state(ts))
 780                         Rt = ts->pressure_max / 2;
 781                 else
 782                         Rt = 0;
 783                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 784         } else if (likely(x && z1)) {
 785                 /* compute touch pressure resistance using equation #2 */
 786                 Rt = z2;
 787                 Rt -= z1;
 788                 Rt *= x;
 789                 Rt *= ts->x_plate_ohms;
 790                 Rt /= z1;
 791                 Rt = (Rt + 2047) >> 12;
 792         } else {
 793                 Rt = 0;
 794         }
 795 
 796         /*
 797          * Sample found inconsistent by debouncing or pressure is beyond
 798          * the maximum. Don't report it to user space, repeat at least
 799          * once more the measurement
 800          */
 801         if (packet->tc.ignore || Rt > ts->pressure_max) {
 802                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 803                          packet->tc.ignore, Rt);
 804                 return;
 805         }
 806 
 807         /*
 808          * Maybe check the pendown state before reporting. This discards
 809          * false readings when the pen is lifted.
 810          */
 811         if (ts->penirq_recheck_delay_usecs) {
 812                 udelay(ts->penirq_recheck_delay_usecs);
 813                 if (!get_pendown_state(ts))
 814                         Rt = 0;
 815         }
 816 
 817         /*
 818          * NOTE: We can't rely on the pressure to determine the pen down
 819          * state, even this controller has a pressure sensor. The pressure
 820          * value can fluctuate for quite a while after lifting the pen and
 821          * in some cases may not even settle at the expected value.
 822          *
 823          * The only safe way to check for the pen up condition is in the
 824          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 825          */
 826         if (Rt) {
 827                 struct input_dev *input = ts->input;
 828 
 829                 if (!ts->pendown) {
 830                         input_report_key(input, BTN_TOUCH, 1);
 831                         ts->pendown = true;
 832                         dev_vdbg(&ts->spi->dev, "DOWN\n");
 833                 }
 834 
 835                 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
 836                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 837 
 838                 input_sync(input);
 839                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
 840         }
 841 }
 842 
 843 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 844 {
 845         struct ads7846 *ts = handle;
 846 
 847         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 848 }
 849 
 850 
 851 static irqreturn_t ads7846_irq(int irq, void *handle)
 852 {
 853         struct ads7846 *ts = handle;
 854 
 855         /* Start with a small delay before checking pendown state */
 856         msleep(TS_POLL_DELAY);
 857 
 858         while (!ts->stopped && get_pendown_state(ts)) {
 859 
 860                 /* pen is down, continue with the measurement */
 861                 ads7846_read_state(ts);
 862 
 863                 if (!ts->stopped)
 864                         ads7846_report_state(ts);
 865 
 866                 wait_event_timeout(ts->wait, ts->stopped,
 867                                    msecs_to_jiffies(TS_POLL_PERIOD));
 868         }
 869 
 870         if (ts->pendown && !ts->stopped) {
 871                 struct input_dev *input = ts->input;
 872 
 873                 input_report_key(input, BTN_TOUCH, 0);
 874                 input_report_abs(input, ABS_PRESSURE, 0);
 875                 input_sync(input);
 876 
 877                 ts->pendown = false;
 878                 dev_vdbg(&ts->spi->dev, "UP\n");
 879         }
 880 
 881         return IRQ_HANDLED;
 882 }
 883 
 884 static int __maybe_unused ads7846_suspend(struct device *dev)
 885 {
 886         struct ads7846 *ts = dev_get_drvdata(dev);
 887 
 888         mutex_lock(&ts->lock);
 889 
 890         if (!ts->suspended) {
 891 
 892                 if (!ts->disabled)
 893                         __ads7846_disable(ts);
 894 
 895                 if (device_may_wakeup(&ts->spi->dev))
 896                         enable_irq_wake(ts->spi->irq);
 897 
 898                 ts->suspended = true;
 899         }
 900 
 901         mutex_unlock(&ts->lock);
 902 
 903         return 0;
 904 }
 905 
 906 static int __maybe_unused ads7846_resume(struct device *dev)
 907 {
 908         struct ads7846 *ts = dev_get_drvdata(dev);
 909 
 910         mutex_lock(&ts->lock);
 911 
 912         if (ts->suspended) {
 913 
 914                 ts->suspended = false;
 915 
 916                 if (device_may_wakeup(&ts->spi->dev))
 917                         disable_irq_wake(ts->spi->irq);
 918 
 919                 if (!ts->disabled)
 920                         __ads7846_enable(ts);
 921         }
 922 
 923         mutex_unlock(&ts->lock);
 924 
 925         return 0;
 926 }
 927 
 928 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 929 
 930 static int ads7846_setup_pendown(struct spi_device *spi,
 931                                  struct ads7846 *ts,
 932                                  const struct ads7846_platform_data *pdata)
 933 {
 934         int err;
 935 
 936         /*
 937          * REVISIT when the irq can be triggered active-low, or if for some
 938          * reason the touchscreen isn't hooked up, we don't need to access
 939          * the pendown state.
 940          */
 941 
 942         if (pdata->get_pendown_state) {
 943                 ts->get_pendown_state = pdata->get_pendown_state;
 944         } else if (gpio_is_valid(pdata->gpio_pendown)) {
 945 
 946                 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
 947                                        "ads7846_pendown");
 948                 if (err) {
 949                         dev_err(&spi->dev,
 950                                 "failed to request/setup pendown GPIO%d: %d\n",
 951                                 pdata->gpio_pendown, err);
 952                         return err;
 953                 }
 954 
 955                 ts->gpio_pendown = pdata->gpio_pendown;
 956 
 957                 if (pdata->gpio_pendown_debounce)
 958                         gpio_set_debounce(pdata->gpio_pendown,
 959                                           pdata->gpio_pendown_debounce);
 960         } else {
 961                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 962                 return -EINVAL;
 963         }
 964 
 965         return 0;
 966 }
 967 
 968 /*
 969  * Set up the transfers to read touchscreen state; this assumes we
 970  * use formula #2 for pressure, not #3.
 971  */
 972 static void ads7846_setup_spi_msg(struct ads7846 *ts,
 973                                   const struct ads7846_platform_data *pdata)
 974 {
 975         struct spi_message *m = &ts->msg[0];
 976         struct spi_transfer *x = ts->xfer;
 977         struct ads7846_packet *packet = ts->packet;
 978         int vref = pdata->keep_vref_on;
 979 
 980         if (ts->model == 7873) {
 981                 /*
 982                  * The AD7873 is almost identical to the ADS7846
 983                  * keep VREF off during differential/ratiometric
 984                  * conversion modes.
 985                  */
 986                 ts->model = 7846;
 987                 vref = 0;
 988         }
 989 
 990         ts->msg_count = 1;
 991         spi_message_init(m);
 992         m->context = ts;
 993 
 994         if (ts->model == 7845) {
 995                 packet->read_y_cmd[0] = READ_Y(vref);
 996                 packet->read_y_cmd[1] = 0;
 997                 packet->read_y_cmd[2] = 0;
 998                 x->tx_buf = &packet->read_y_cmd[0];
 999                 x->rx_buf = &packet->tc.y_buf[0];
1000                 x->len = 3;
1001                 spi_message_add_tail(x, m);
1002         } else {
1003                 /* y- still on; turn on only y+ (and ADC) */
1004                 packet->read_y = READ_Y(vref);
1005                 x->tx_buf = &packet->read_y;
1006                 x->len = 1;
1007                 spi_message_add_tail(x, m);
1008 
1009                 x++;
1010                 x->rx_buf = &packet->tc.y;
1011                 x->len = 2;
1012                 spi_message_add_tail(x, m);
1013         }
1014 
1015         /*
1016          * The first sample after switching drivers can be low quality;
1017          * optionally discard it, using a second one after the signals
1018          * have had enough time to stabilize.
1019          */
1020         if (pdata->settle_delay_usecs) {
1021                 x->delay_usecs = pdata->settle_delay_usecs;
1022 
1023                 x++;
1024                 x->tx_buf = &packet->read_y;
1025                 x->len = 1;
1026                 spi_message_add_tail(x, m);
1027 
1028                 x++;
1029                 x->rx_buf = &packet->tc.y;
1030                 x->len = 2;
1031                 spi_message_add_tail(x, m);
1032         }
1033 
1034         ts->msg_count++;
1035         m++;
1036         spi_message_init(m);
1037         m->context = ts;
1038 
1039         if (ts->model == 7845) {
1040                 x++;
1041                 packet->read_x_cmd[0] = READ_X(vref);
1042                 packet->read_x_cmd[1] = 0;
1043                 packet->read_x_cmd[2] = 0;
1044                 x->tx_buf = &packet->read_x_cmd[0];
1045                 x->rx_buf = &packet->tc.x_buf[0];
1046                 x->len = 3;
1047                 spi_message_add_tail(x, m);
1048         } else {
1049                 /* turn y- off, x+ on, then leave in lowpower */
1050                 x++;
1051                 packet->read_x = READ_X(vref);
1052                 x->tx_buf = &packet->read_x;
1053                 x->len = 1;
1054                 spi_message_add_tail(x, m);
1055 
1056                 x++;
1057                 x->rx_buf = &packet->tc.x;
1058                 x->len = 2;
1059                 spi_message_add_tail(x, m);
1060         }
1061 
1062         /* ... maybe discard first sample ... */
1063         if (pdata->settle_delay_usecs) {
1064                 x->delay_usecs = pdata->settle_delay_usecs;
1065 
1066                 x++;
1067                 x->tx_buf = &packet->read_x;
1068                 x->len = 1;
1069                 spi_message_add_tail(x, m);
1070 
1071                 x++;
1072                 x->rx_buf = &packet->tc.x;
1073                 x->len = 2;
1074                 spi_message_add_tail(x, m);
1075         }
1076 
1077         /* turn y+ off, x- on; we'll use formula #2 */
1078         if (ts->model == 7846) {
1079                 ts->msg_count++;
1080                 m++;
1081                 spi_message_init(m);
1082                 m->context = ts;
1083 
1084                 x++;
1085                 packet->read_z1 = READ_Z1(vref);
1086                 x->tx_buf = &packet->read_z1;
1087                 x->len = 1;
1088                 spi_message_add_tail(x, m);
1089 
1090                 x++;
1091                 x->rx_buf = &packet->tc.z1;
1092                 x->len = 2;
1093                 spi_message_add_tail(x, m);
1094 
1095                 /* ... maybe discard first sample ... */
1096                 if (pdata->settle_delay_usecs) {
1097                         x->delay_usecs = pdata->settle_delay_usecs;
1098 
1099                         x++;
1100                         x->tx_buf = &packet->read_z1;
1101                         x->len = 1;
1102                         spi_message_add_tail(x, m);
1103 
1104                         x++;
1105                         x->rx_buf = &packet->tc.z1;
1106                         x->len = 2;
1107                         spi_message_add_tail(x, m);
1108                 }
1109 
1110                 ts->msg_count++;
1111                 m++;
1112                 spi_message_init(m);
1113                 m->context = ts;
1114 
1115                 x++;
1116                 packet->read_z2 = READ_Z2(vref);
1117                 x->tx_buf = &packet->read_z2;
1118                 x->len = 1;
1119                 spi_message_add_tail(x, m);
1120 
1121                 x++;
1122                 x->rx_buf = &packet->tc.z2;
1123                 x->len = 2;
1124                 spi_message_add_tail(x, m);
1125 
1126                 /* ... maybe discard first sample ... */
1127                 if (pdata->settle_delay_usecs) {
1128                         x->delay_usecs = pdata->settle_delay_usecs;
1129 
1130                         x++;
1131                         x->tx_buf = &packet->read_z2;
1132                         x->len = 1;
1133                         spi_message_add_tail(x, m);
1134 
1135                         x++;
1136                         x->rx_buf = &packet->tc.z2;
1137                         x->len = 2;
1138                         spi_message_add_tail(x, m);
1139                 }
1140         }
1141 
1142         /* power down */
1143         ts->msg_count++;
1144         m++;
1145         spi_message_init(m);
1146         m->context = ts;
1147 
1148         if (ts->model == 7845) {
1149                 x++;
1150                 packet->pwrdown_cmd[0] = PWRDOWN;
1151                 packet->pwrdown_cmd[1] = 0;
1152                 packet->pwrdown_cmd[2] = 0;
1153                 x->tx_buf = &packet->pwrdown_cmd[0];
1154                 x->len = 3;
1155         } else {
1156                 x++;
1157                 packet->pwrdown = PWRDOWN;
1158                 x->tx_buf = &packet->pwrdown;
1159                 x->len = 1;
1160                 spi_message_add_tail(x, m);
1161 
1162                 x++;
1163                 x->rx_buf = &packet->dummy;
1164                 x->len = 2;
1165         }
1166 
1167         CS_CHANGE(*x);
1168         spi_message_add_tail(x, m);
1169 }
1170 
1171 #ifdef CONFIG_OF
1172 static const struct of_device_id ads7846_dt_ids[] = {
1173         { .compatible = "ti,tsc2046",   .data = (void *) 7846 },
1174         { .compatible = "ti,ads7843",   .data = (void *) 7843 },
1175         { .compatible = "ti,ads7845",   .data = (void *) 7845 },
1176         { .compatible = "ti,ads7846",   .data = (void *) 7846 },
1177         { .compatible = "ti,ads7873",   .data = (void *) 7873 },
1178         { }
1179 };
1180 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1181 
1182 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1183 {
1184         struct ads7846_platform_data *pdata;
1185         struct device_node *node = dev->of_node;
1186         const struct of_device_id *match;
1187         u32 value;
1188 
1189         if (!node) {
1190                 dev_err(dev, "Device does not have associated DT data\n");
1191                 return ERR_PTR(-EINVAL);
1192         }
1193 
1194         match = of_match_device(ads7846_dt_ids, dev);
1195         if (!match) {
1196                 dev_err(dev, "Unknown device model\n");
1197                 return ERR_PTR(-EINVAL);
1198         }
1199 
1200         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1201         if (!pdata)
1202                 return ERR_PTR(-ENOMEM);
1203 
1204         pdata->model = (unsigned long)match->data;
1205 
1206         of_property_read_u16(node, "ti,vref-delay-usecs",
1207                              &pdata->vref_delay_usecs);
1208         of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1209         pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1210 
1211         pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1212 
1213         of_property_read_u16(node, "ti,settle-delay-usec",
1214                              &pdata->settle_delay_usecs);
1215         of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1216                              &pdata->penirq_recheck_delay_usecs);
1217 
1218         of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1219         of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1220 
1221         of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1222         of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1223         of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1224         of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1225 
1226         /*
1227          * touchscreen-max-pressure gets parsed during
1228          * touchscreen_parse_properties()
1229          */
1230         of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1231         if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1232                 pdata->pressure_min = (u16) value;
1233         of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1234 
1235         of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1236         if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1237                 pdata->debounce_max = (u16) value;
1238         of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1239         of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1240 
1241         of_property_read_u32(node, "ti,pendown-gpio-debounce",
1242                              &pdata->gpio_pendown_debounce);
1243 
1244         pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1245                         of_property_read_bool(node, "linux,wakeup");
1246 
1247         pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1248 
1249         return pdata;
1250 }
1251 #else
1252 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1253 {
1254         dev_err(dev, "no platform data defined\n");
1255         return ERR_PTR(-EINVAL);
1256 }
1257 #endif
1258 
1259 static int ads7846_probe(struct spi_device *spi)
1260 {
1261         const struct ads7846_platform_data *pdata;
1262         struct ads7846 *ts;
1263         struct ads7846_packet *packet;
1264         struct input_dev *input_dev;
1265         unsigned long irq_flags;
1266         int err;
1267 
1268         if (!spi->irq) {
1269                 dev_dbg(&spi->dev, "no IRQ?\n");
1270                 return -EINVAL;
1271         }
1272 
1273         /* don't exceed max specified sample rate */
1274         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1275                 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1276                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1277                 return -EINVAL;
1278         }
1279 
1280         /*
1281          * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1282          * that even if the hardware can do that, the SPI controller driver
1283          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1284          */
1285         spi->bits_per_word = 8;
1286         spi->mode = SPI_MODE_0;
1287         err = spi_setup(spi);
1288         if (err < 0)
1289                 return err;
1290 
1291         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1292         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1293         input_dev = input_allocate_device();
1294         if (!ts || !packet || !input_dev) {
1295                 err = -ENOMEM;
1296                 goto err_free_mem;
1297         }
1298 
1299         spi_set_drvdata(spi, ts);
1300 
1301         ts->packet = packet;
1302         ts->spi = spi;
1303         ts->input = input_dev;
1304 
1305         mutex_init(&ts->lock);
1306         init_waitqueue_head(&ts->wait);
1307 
1308         pdata = dev_get_platdata(&spi->dev);
1309         if (!pdata) {
1310                 pdata = ads7846_probe_dt(&spi->dev);
1311                 if (IS_ERR(pdata)) {
1312                         err = PTR_ERR(pdata);
1313                         goto err_free_mem;
1314                 }
1315         }
1316 
1317         ts->model = pdata->model ? : 7846;
1318         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1319         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1320         ts->vref_mv = pdata->vref_mv;
1321 
1322         if (pdata->filter != NULL) {
1323                 if (pdata->filter_init != NULL) {
1324                         err = pdata->filter_init(pdata, &ts->filter_data);
1325                         if (err < 0)
1326                                 goto err_free_mem;
1327                 }
1328                 ts->filter = pdata->filter;
1329                 ts->filter_cleanup = pdata->filter_cleanup;
1330         } else if (pdata->debounce_max) {
1331                 ts->debounce_max = pdata->debounce_max;
1332                 if (ts->debounce_max < 2)
1333                         ts->debounce_max = 2;
1334                 ts->debounce_tol = pdata->debounce_tol;
1335                 ts->debounce_rep = pdata->debounce_rep;
1336                 ts->filter = ads7846_debounce_filter;
1337                 ts->filter_data = ts;
1338         } else {
1339                 ts->filter = ads7846_no_filter;
1340         }
1341 
1342         err = ads7846_setup_pendown(spi, ts, pdata);
1343         if (err)
1344                 goto err_cleanup_filter;
1345 
1346         if (pdata->penirq_recheck_delay_usecs)
1347                 ts->penirq_recheck_delay_usecs =
1348                                 pdata->penirq_recheck_delay_usecs;
1349 
1350         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1351 
1352         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1353         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1354 
1355         input_dev->name = ts->name;
1356         input_dev->phys = ts->phys;
1357         input_dev->dev.parent = &spi->dev;
1358 
1359         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1360         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1361         input_set_abs_params(input_dev, ABS_X,
1362                         pdata->x_min ? : 0,
1363                         pdata->x_max ? : MAX_12BIT,
1364                         0, 0);
1365         input_set_abs_params(input_dev, ABS_Y,
1366                         pdata->y_min ? : 0,
1367                         pdata->y_max ? : MAX_12BIT,
1368                         0, 0);
1369         input_set_abs_params(input_dev, ABS_PRESSURE,
1370                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1371 
1372         /*
1373          * Parse common framework properties. Must be done here to ensure the
1374          * correct behaviour in case of using the legacy vendor bindings. The
1375          * general binding value overrides the vendor specific one.
1376          */
1377         touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1378         ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1379 
1380         /*
1381          * Check if legacy ti,swap-xy binding is used instead of
1382          * touchscreen-swapped-x-y
1383          */
1384         if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1385                 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1386                 ts->core_prop.swap_x_y = true;
1387         }
1388 
1389         ads7846_setup_spi_msg(ts, pdata);
1390 
1391         ts->reg = regulator_get(&spi->dev, "vcc");
1392         if (IS_ERR(ts->reg)) {
1393                 err = PTR_ERR(ts->reg);
1394                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1395                 goto err_free_gpio;
1396         }
1397 
1398         err = regulator_enable(ts->reg);
1399         if (err) {
1400                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1401                 goto err_put_regulator;
1402         }
1403 
1404         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1405         irq_flags |= IRQF_ONESHOT;
1406 
1407         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1408                                    irq_flags, spi->dev.driver->name, ts);
1409         if (err && !pdata->irq_flags) {
1410                 dev_info(&spi->dev,
1411                         "trying pin change workaround on irq %d\n", spi->irq);
1412                 irq_flags |= IRQF_TRIGGER_RISING;
1413                 err = request_threaded_irq(spi->irq,
1414                                   ads7846_hard_irq, ads7846_irq,
1415                                   irq_flags, spi->dev.driver->name, ts);
1416         }
1417 
1418         if (err) {
1419                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1420                 goto err_disable_regulator;
1421         }
1422 
1423         err = ads784x_hwmon_register(spi, ts);
1424         if (err)
1425                 goto err_free_irq;
1426 
1427         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1428 
1429         /*
1430          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1431          * the touchscreen, in case it's not connected.
1432          */
1433         if (ts->model == 7845)
1434                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1435         else
1436                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1437 
1438         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1439         if (err)
1440                 goto err_remove_hwmon;
1441 
1442         err = input_register_device(input_dev);
1443         if (err)
1444                 goto err_remove_attr_group;
1445 
1446         device_init_wakeup(&spi->dev, pdata->wakeup);
1447 
1448         /*
1449          * If device does not carry platform data we must have allocated it
1450          * when parsing DT data.
1451          */
1452         if (!dev_get_platdata(&spi->dev))
1453                 devm_kfree(&spi->dev, (void *)pdata);
1454 
1455         return 0;
1456 
1457  err_remove_attr_group:
1458         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1459  err_remove_hwmon:
1460         ads784x_hwmon_unregister(spi, ts);
1461  err_free_irq:
1462         free_irq(spi->irq, ts);
1463  err_disable_regulator:
1464         regulator_disable(ts->reg);
1465  err_put_regulator:
1466         regulator_put(ts->reg);
1467  err_free_gpio:
1468         if (!ts->get_pendown_state)
1469                 gpio_free(ts->gpio_pendown);
1470  err_cleanup_filter:
1471         if (ts->filter_cleanup)
1472                 ts->filter_cleanup(ts->filter_data);
1473  err_free_mem:
1474         input_free_device(input_dev);
1475         kfree(packet);
1476         kfree(ts);
1477         return err;
1478 }
1479 
1480 static int ads7846_remove(struct spi_device *spi)
1481 {
1482         struct ads7846 *ts = spi_get_drvdata(spi);
1483 
1484         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1485 
1486         ads7846_disable(ts);
1487         free_irq(ts->spi->irq, ts);
1488 
1489         input_unregister_device(ts->input);
1490 
1491         ads784x_hwmon_unregister(spi, ts);
1492 
1493         regulator_put(ts->reg);
1494 
1495         if (!ts->get_pendown_state) {
1496                 /*
1497                  * If we are not using specialized pendown method we must
1498                  * have been relying on gpio we set up ourselves.
1499                  */
1500                 gpio_free(ts->gpio_pendown);
1501         }
1502 
1503         if (ts->filter_cleanup)
1504                 ts->filter_cleanup(ts->filter_data);
1505 
1506         kfree(ts->packet);
1507         kfree(ts);
1508 
1509         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1510 
1511         return 0;
1512 }
1513 
1514 static struct spi_driver ads7846_driver = {
1515         .driver = {
1516                 .name   = "ads7846",
1517                 .pm     = &ads7846_pm,
1518                 .of_match_table = of_match_ptr(ads7846_dt_ids),
1519         },
1520         .probe          = ads7846_probe,
1521         .remove         = ads7846_remove,
1522 };
1523 
1524 module_spi_driver(ads7846_driver);
1525 
1526 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1527 MODULE_LICENSE("GPL");
1528 MODULE_ALIAS("spi:ads7846");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/input/touchscreen/ads7846.c

DEFINITIONS
