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/property.h> 28 #include <linux/gpio/consumer.h> 29 #include <linux/spi/spi.h> 30 #include <linux/spi/ads7846.h> 31 #include <linux/regulator/consumer.h> 32 #include <linux/module.h> 33 #include <linux/unaligned.h> 34 35 /* 36 * This code has been heavily tested on a Nokia 770, and lightly 37 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 38 * TSC2046 is just newer ads7846 silicon. 39 * Support for ads7843 tested on Atmel at91sam926x-EK. 40 * Support for ads7845 has only been stubbed in. 41 * Support for Analog Devices AD7873 and AD7843 tested. 42 * 43 * IRQ handling needs a workaround because of a shortcoming in handling 44 * edge triggered IRQs on some platforms like the OMAP1/2. These 45 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 46 * have to maintain our own SW IRQ disabled status. This should be 47 * removed as soon as the affected platform's IRQ handling is fixed. 48 * 49 * App note sbaa036 talks in more detail about accurate sampling... 50 * that ought to help in situations like LCDs inducing noise (which 51 * can also be helped by using synch signals) and more generally. 52 * This driver tries to utilize the measures described in the app 53 * note. The strength of filtering can be set in the board-* specific 54 * files. 55 */ 56 57 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 58 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 59 60 /* this driver doesn't aim at the peak continuous sample rate */ 61 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 62 63 struct ads7846_buf { 64 u8 cmd; 65 __be16 data; 66 } __packed; 67 68 struct ads7846_buf_layout { 69 unsigned int offset; 70 unsigned int count; 71 unsigned int skip; 72 }; 73 74 /* 75 * We allocate this separately to avoid cache line sharing issues when 76 * driver is used with DMA-based SPI controllers (like atmel_spi) on 77 * systems where main memory is not DMA-coherent (most non-x86 boards). 78 */ 79 struct ads7846_packet { 80 unsigned int count; 81 unsigned int count_skip; 82 unsigned int cmds; 83 unsigned int last_cmd_idx; 84 struct ads7846_buf_layout l[5]; 85 struct ads7846_buf *rx; 86 struct ads7846_buf *tx; 87 88 struct ads7846_buf pwrdown_cmd; 89 90 bool ignore; 91 u16 x, y, z1, z2; 92 }; 93 94 struct ads7846 { 95 struct input_dev *input; 96 char phys[32]; 97 char name[32]; 98 99 struct spi_device *spi; 100 struct regulator *reg; 101 102 u16 model; 103 u16 vref_mv; 104 u16 vref_delay_usecs; 105 u16 x_plate_ohms; 106 u16 pressure_max; 107 108 bool swap_xy; 109 bool use_internal; 110 111 struct ads7846_packet *packet; 112 113 struct spi_transfer xfer[18]; 114 struct spi_message msg[5]; 115 int msg_count; 116 wait_queue_head_t wait; 117 118 bool pendown; 119 120 int read_cnt; 121 int read_rep; 122 int last_read; 123 124 u16 debounce_max; 125 u16 debounce_tol; 126 u16 debounce_rep; 127 128 u16 penirq_recheck_delay_usecs; 129 130 struct touchscreen_properties core_prop; 131 132 struct mutex lock; 133 bool stopped; /* P: lock */ 134 bool disabled; /* P: lock */ 135 bool suspended; /* P: lock */ 136 137 int (*filter)(void *data, int data_idx, int *val); 138 void *filter_data; 139 int (*get_pendown_state)(void); 140 struct gpio_desc *gpio_pendown; 141 struct gpio_desc *gpio_hsync; 142 143 void (*wait_for_sync)(void); 144 }; 145 146 enum ads7846_filter { 147 ADS7846_FILTER_OK, 148 ADS7846_FILTER_REPEAT, 149 ADS7846_FILTER_IGNORE, 150 }; 151 152 /* leave chip selected when we're done, for quicker re-select? */ 153 #if 0 154 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 155 #else 156 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 157 #endif 158 159 /*--------------------------------------------------------------------------*/ 160 161 /* The ADS7846 has touchscreen and other sensors. 162 * Earlier ads784x chips are somewhat compatible. 163 */ 164 #define ADS_START (1 << 7) 165 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 166 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 167 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 168 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 169 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 170 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 171 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 172 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 173 #define ADS_8_BIT (1 << 3) 174 #define ADS_12_BIT (0 << 3) 175 #define ADS_SER (1 << 2) /* non-differential */ 176 #define ADS_DFR (0 << 2) /* differential */ 177 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 178 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 179 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 180 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 181 182 #define MAX_12BIT ((1<<12)-1) 183 184 /* leave ADC powered up (disables penirq) between differential samples */ 185 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 186 | ADS_12_BIT | ADS_DFR | \ 187 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 188 189 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 190 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 191 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 192 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 193 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 194 195 /* single-ended samples need to first power up reference voltage; 196 * we leave both ADC and VREF powered 197 */ 198 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 199 | ADS_12_BIT | ADS_SER) 200 201 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 202 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 203 204 /* Order commands in the most optimal way to reduce Vref switching and 205 * settling time: 206 * Measure: X; Vref: X+, X-; IN: Y+ 207 * Measure: Y; Vref: Y+, Y-; IN: X+ 208 * Measure: Z1; Vref: Y+, X-; IN: X+ 209 * Measure: Z2; Vref: Y+, X-; IN: Y- 210 */ 211 enum ads7846_cmds { 212 ADS7846_X, 213 ADS7846_Y, 214 ADS7846_Z1, 215 ADS7846_Z2, 216 ADS7846_PWDOWN, 217 }; 218 219 static int get_pendown_state(struct ads7846 *ts) 220 { 221 if (ts->get_pendown_state) 222 return ts->get_pendown_state(); 223 224 return gpiod_get_value(ts->gpio_pendown); 225 } 226 227 static void ads7846_report_pen_up(struct ads7846 *ts) 228 { 229 struct input_dev *input = ts->input; 230 231 input_report_key(input, BTN_TOUCH, 0); 232 input_report_abs(input, ABS_PRESSURE, 0); 233 input_sync(input); 234 235 ts->pendown = false; 236 dev_vdbg(&ts->spi->dev, "UP\n"); 237 } 238 239 /* Must be called with ts->lock held */ 240 static void ads7846_stop(struct ads7846 *ts) 241 { 242 if (!ts->disabled && !ts->suspended) { 243 /* Signal IRQ thread to stop polling and disable the handler. */ 244 ts->stopped = true; 245 mb(); 246 wake_up(&ts->wait); 247 disable_irq(ts->spi->irq); 248 } 249 } 250 251 /* Must be called with ts->lock held */ 252 static void ads7846_restart(struct ads7846 *ts) 253 { 254 if (!ts->disabled && !ts->suspended) { 255 /* Check if pen was released since last stop */ 256 if (ts->pendown && !get_pendown_state(ts)) 257 ads7846_report_pen_up(ts); 258 259 /* Tell IRQ thread that it may poll the device. */ 260 ts->stopped = false; 261 mb(); 262 enable_irq(ts->spi->irq); 263 } 264 } 265 266 /* Must be called with ts->lock held */ 267 static void __ads7846_disable(struct ads7846 *ts) 268 { 269 ads7846_stop(ts); 270 regulator_disable(ts->reg); 271 272 /* 273 * We know the chip's in low power mode since we always 274 * leave it that way after every request 275 */ 276 } 277 278 /* Must be called with ts->lock held */ 279 static void __ads7846_enable(struct ads7846 *ts) 280 { 281 int error; 282 283 error = regulator_enable(ts->reg); 284 if (error != 0) 285 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 286 287 ads7846_restart(ts); 288 } 289 290 static void ads7846_disable(struct ads7846 *ts) 291 { 292 mutex_lock(&ts->lock); 293 294 if (!ts->disabled) { 295 296 if (!ts->suspended) 297 __ads7846_disable(ts); 298 299 ts->disabled = true; 300 } 301 302 mutex_unlock(&ts->lock); 303 } 304 305 static void ads7846_enable(struct ads7846 *ts) 306 { 307 mutex_lock(&ts->lock); 308 309 if (ts->disabled) { 310 311 ts->disabled = false; 312 313 if (!ts->suspended) 314 __ads7846_enable(ts); 315 } 316 317 mutex_unlock(&ts->lock); 318 } 319 320 /*--------------------------------------------------------------------------*/ 321 322 /* 323 * Non-touchscreen sensors only use single-ended conversions. 324 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 325 * ads7846 lets that pin be unconnected, to use internal vREF. 326 */ 327 328 struct ser_req { 329 u8 ref_on; 330 u8 command; 331 u8 ref_off; 332 u16 scratch; 333 struct spi_message msg; 334 struct spi_transfer xfer[6]; 335 /* 336 * DMA (thus cache coherency maintenance) requires the 337 * transfer buffers to live in their own cache lines. 338 */ 339 __be16 sample ____cacheline_aligned; 340 }; 341 342 struct ads7845_ser_req { 343 u8 command[3]; 344 struct spi_message msg; 345 struct spi_transfer xfer[2]; 346 /* 347 * DMA (thus cache coherency maintenance) requires the 348 * transfer buffers to live in their own cache lines. 349 */ 350 u8 sample[3] ____cacheline_aligned; 351 }; 352 353 static int ads7846_read12_ser(struct device *dev, unsigned command) 354 { 355 struct spi_device *spi = to_spi_device(dev); 356 struct ads7846 *ts = dev_get_drvdata(dev); 357 struct ser_req *req; 358 int status; 359 360 req = kzalloc(sizeof *req, GFP_KERNEL); 361 if (!req) 362 return -ENOMEM; 363 364 spi_message_init(&req->msg); 365 366 /* maybe turn on internal vREF, and let it settle */ 367 if (ts->use_internal) { 368 req->ref_on = REF_ON; 369 req->xfer[0].tx_buf = &req->ref_on; 370 req->xfer[0].len = 1; 371 spi_message_add_tail(&req->xfer[0], &req->msg); 372 373 req->xfer[1].rx_buf = &req->scratch; 374 req->xfer[1].len = 2; 375 376 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 377 req->xfer[1].delay.value = ts->vref_delay_usecs; 378 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 379 spi_message_add_tail(&req->xfer[1], &req->msg); 380 381 /* Enable reference voltage */ 382 command |= ADS_PD10_REF_ON; 383 } 384 385 /* Enable ADC in every case */ 386 command |= ADS_PD10_ADC_ON; 387 388 /* take sample */ 389 req->command = (u8) command; 390 req->xfer[2].tx_buf = &req->command; 391 req->xfer[2].len = 1; 392 spi_message_add_tail(&req->xfer[2], &req->msg); 393 394 req->xfer[3].rx_buf = &req->sample; 395 req->xfer[3].len = 2; 396 spi_message_add_tail(&req->xfer[3], &req->msg); 397 398 /* REVISIT: take a few more samples, and compare ... */ 399 400 /* converter in low power mode & enable PENIRQ */ 401 req->ref_off = PWRDOWN; 402 req->xfer[4].tx_buf = &req->ref_off; 403 req->xfer[4].len = 1; 404 spi_message_add_tail(&req->xfer[4], &req->msg); 405 406 req->xfer[5].rx_buf = &req->scratch; 407 req->xfer[5].len = 2; 408 CS_CHANGE(req->xfer[5]); 409 spi_message_add_tail(&req->xfer[5], &req->msg); 410 411 mutex_lock(&ts->lock); 412 ads7846_stop(ts); 413 status = spi_sync(spi, &req->msg); 414 ads7846_restart(ts); 415 mutex_unlock(&ts->lock); 416 417 if (status == 0) { 418 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 419 status = be16_to_cpu(req->sample); 420 status = status >> 3; 421 status &= 0x0fff; 422 } 423 424 kfree(req); 425 return status; 426 } 427 428 static int ads7845_read12_ser(struct device *dev, unsigned command) 429 { 430 struct spi_device *spi = to_spi_device(dev); 431 struct ads7846 *ts = dev_get_drvdata(dev); 432 struct ads7845_ser_req *req; 433 int status; 434 435 req = kzalloc(sizeof *req, GFP_KERNEL); 436 if (!req) 437 return -ENOMEM; 438 439 spi_message_init(&req->msg); 440 441 req->command[0] = (u8) command; 442 req->xfer[0].tx_buf = req->command; 443 req->xfer[0].rx_buf = req->sample; 444 req->xfer[0].len = 3; 445 spi_message_add_tail(&req->xfer[0], &req->msg); 446 447 mutex_lock(&ts->lock); 448 ads7846_stop(ts); 449 status = spi_sync(spi, &req->msg); 450 ads7846_restart(ts); 451 mutex_unlock(&ts->lock); 452 453 if (status == 0) { 454 /* BE12 value, then padding */ 455 status = get_unaligned_be16(&req->sample[1]); 456 status = status >> 3; 457 status &= 0x0fff; 458 } 459 460 kfree(req); 461 return status; 462 } 463 464 #if IS_ENABLED(CONFIG_HWMON) 465 466 #define SHOW(name, var, adjust) static ssize_t \ 467 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 468 { \ 469 struct ads7846 *ts = dev_get_drvdata(dev); \ 470 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 471 READ_12BIT_SER(var)); \ 472 if (v < 0) \ 473 return v; \ 474 return sprintf(buf, "%u\n", adjust(ts, v)); \ 475 } \ 476 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 477 478 479 /* Sysfs conventions report temperatures in millidegrees Celsius. 480 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 481 * accuracy scheme without calibration data. For now we won't try either; 482 * userspace sees raw sensor values, and must scale/calibrate appropriately. 483 */ 484 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 485 { 486 return v; 487 } 488 489 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 490 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 491 492 493 /* sysfs conventions report voltages in millivolts. We can convert voltages 494 * if we know vREF. userspace may need to scale vAUX to match the board's 495 * external resistors; we assume that vBATT only uses the internal ones. 496 */ 497 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 498 { 499 unsigned retval = v; 500 501 /* external resistors may scale vAUX into 0..vREF */ 502 retval *= ts->vref_mv; 503 retval = retval >> 12; 504 505 return retval; 506 } 507 508 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 509 { 510 unsigned retval = vaux_adjust(ts, v); 511 512 /* ads7846 has a resistor ladder to scale this signal down */ 513 if (ts->model == 7846) 514 retval *= 4; 515 516 return retval; 517 } 518 519 SHOW(in0_input, vaux, vaux_adjust) 520 SHOW(in1_input, vbatt, vbatt_adjust) 521 522 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 523 int index) 524 { 525 struct device *dev = kobj_to_dev(kobj); 526 struct ads7846 *ts = dev_get_drvdata(dev); 527 528 if (ts->model == 7843 && index < 2) /* in0, in1 */ 529 return 0; 530 if (ts->model == 7845 && index != 2) /* in0 */ 531 return 0; 532 533 return attr->mode; 534 } 535 536 static struct attribute *ads7846_attributes[] = { 537 &dev_attr_temp0.attr, /* 0 */ 538 &dev_attr_temp1.attr, /* 1 */ 539 &dev_attr_in0_input.attr, /* 2 */ 540 &dev_attr_in1_input.attr, /* 3 */ 541 NULL, 542 }; 543 544 static const struct attribute_group ads7846_attr_group = { 545 .attrs = ads7846_attributes, 546 .is_visible = ads7846_is_visible, 547 }; 548 __ATTRIBUTE_GROUPS(ads7846_attr); 549 550 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 551 { 552 struct device *hwmon; 553 554 /* hwmon sensors need a reference voltage */ 555 switch (ts->model) { 556 case 7846: 557 if (!ts->vref_mv) { 558 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 559 ts->vref_mv = 2500; 560 ts->use_internal = true; 561 } 562 break; 563 case 7845: 564 case 7843: 565 if (!ts->vref_mv) { 566 dev_warn(&spi->dev, 567 "external vREF for ADS%d not specified\n", 568 ts->model); 569 return 0; 570 } 571 break; 572 } 573 574 hwmon = devm_hwmon_device_register_with_groups(&spi->dev, 575 spi->modalias, ts, 576 ads7846_attr_groups); 577 578 return PTR_ERR_OR_ZERO(hwmon); 579 } 580 581 #else 582 static inline int ads784x_hwmon_register(struct spi_device *spi, 583 struct ads7846 *ts) 584 { 585 return 0; 586 } 587 #endif 588 589 static ssize_t ads7846_pen_down_show(struct device *dev, 590 struct device_attribute *attr, char *buf) 591 { 592 struct ads7846 *ts = dev_get_drvdata(dev); 593 594 return sprintf(buf, "%u\n", ts->pendown); 595 } 596 597 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 598 599 static ssize_t ads7846_disable_show(struct device *dev, 600 struct device_attribute *attr, char *buf) 601 { 602 struct ads7846 *ts = dev_get_drvdata(dev); 603 604 return sprintf(buf, "%u\n", ts->disabled); 605 } 606 607 static ssize_t ads7846_disable_store(struct device *dev, 608 struct device_attribute *attr, 609 const char *buf, size_t count) 610 { 611 struct ads7846 *ts = dev_get_drvdata(dev); 612 unsigned int i; 613 int err; 614 615 err = kstrtouint(buf, 10, &i); 616 if (err) 617 return err; 618 619 if (i) 620 ads7846_disable(ts); 621 else 622 ads7846_enable(ts); 623 624 return count; 625 } 626 627 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 628 629 static struct attribute *ads784x_attrs[] = { 630 &dev_attr_pen_down.attr, 631 &dev_attr_disable.attr, 632 NULL, 633 }; 634 ATTRIBUTE_GROUPS(ads784x); 635 636 /*--------------------------------------------------------------------------*/ 637 638 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 639 { 640 struct ads7846 *ts = ads; 641 642 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 643 /* Start over collecting consistent readings. */ 644 ts->read_rep = 0; 645 /* 646 * Repeat it, if this was the first read or the read 647 * wasn't consistent enough. 648 */ 649 if (ts->read_cnt < ts->debounce_max) { 650 ts->last_read = *val; 651 ts->read_cnt++; 652 return ADS7846_FILTER_REPEAT; 653 } else { 654 /* 655 * Maximum number of debouncing reached and still 656 * not enough number of consistent readings. Abort 657 * the whole sample, repeat it in the next sampling 658 * period. 659 */ 660 ts->read_cnt = 0; 661 return ADS7846_FILTER_IGNORE; 662 } 663 } else { 664 if (++ts->read_rep > ts->debounce_rep) { 665 /* 666 * Got a good reading for this coordinate, 667 * go for the next one. 668 */ 669 ts->read_cnt = 0; 670 ts->read_rep = 0; 671 return ADS7846_FILTER_OK; 672 } else { 673 /* Read more values that are consistent. */ 674 ts->read_cnt++; 675 return ADS7846_FILTER_REPEAT; 676 } 677 } 678 } 679 680 static int ads7846_no_filter(void *ads, int data_idx, int *val) 681 { 682 return ADS7846_FILTER_OK; 683 } 684 685 static int ads7846_get_value(struct ads7846_buf *buf) 686 { 687 int value; 688 689 value = be16_to_cpup(&buf->data); 690 691 /* enforce ADC output is 12 bits width */ 692 return (value >> 3) & 0xfff; 693 } 694 695 static void ads7846_set_cmd_val(struct ads7846 *ts, enum ads7846_cmds cmd_idx, 696 u16 val) 697 { 698 struct ads7846_packet *packet = ts->packet; 699 700 switch (cmd_idx) { 701 case ADS7846_Y: 702 packet->y = val; 703 break; 704 case ADS7846_X: 705 packet->x = val; 706 break; 707 case ADS7846_Z1: 708 packet->z1 = val; 709 break; 710 case ADS7846_Z2: 711 packet->z2 = val; 712 break; 713 default: 714 WARN_ON_ONCE(1); 715 } 716 } 717 718 static u8 ads7846_get_cmd(enum ads7846_cmds cmd_idx, int vref) 719 { 720 switch (cmd_idx) { 721 case ADS7846_Y: 722 return READ_Y(vref); 723 case ADS7846_X: 724 return READ_X(vref); 725 726 /* 7846 specific commands */ 727 case ADS7846_Z1: 728 return READ_Z1(vref); 729 case ADS7846_Z2: 730 return READ_Z2(vref); 731 case ADS7846_PWDOWN: 732 return PWRDOWN; 733 default: 734 WARN_ON_ONCE(1); 735 } 736 737 return 0; 738 } 739 740 static bool ads7846_cmd_need_settle(enum ads7846_cmds cmd_idx) 741 { 742 switch (cmd_idx) { 743 case ADS7846_X: 744 case ADS7846_Y: 745 case ADS7846_Z1: 746 case ADS7846_Z2: 747 return true; 748 case ADS7846_PWDOWN: 749 return false; 750 default: 751 WARN_ON_ONCE(1); 752 } 753 754 return false; 755 } 756 757 static int ads7846_filter(struct ads7846 *ts) 758 { 759 struct ads7846_packet *packet = ts->packet; 760 int action; 761 int val; 762 unsigned int cmd_idx, b; 763 764 packet->ignore = false; 765 for (cmd_idx = packet->last_cmd_idx; cmd_idx < packet->cmds - 1; cmd_idx++) { 766 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 767 768 packet->last_cmd_idx = cmd_idx; 769 770 for (b = l->skip; b < l->count; b++) { 771 val = ads7846_get_value(&packet->rx[l->offset + b]); 772 773 action = ts->filter(ts->filter_data, cmd_idx, &val); 774 if (action == ADS7846_FILTER_REPEAT) { 775 if (b == l->count - 1) 776 return -EAGAIN; 777 } else if (action == ADS7846_FILTER_OK) { 778 ads7846_set_cmd_val(ts, cmd_idx, val); 779 break; 780 } else { 781 packet->ignore = true; 782 return 0; 783 } 784 } 785 } 786 787 return 0; 788 } 789 790 static void ads7846_wait_for_hsync(struct ads7846 *ts) 791 { 792 if (ts->wait_for_sync) { 793 ts->wait_for_sync(); 794 return; 795 } 796 797 if (!ts->gpio_hsync) 798 return; 799 800 /* 801 * Wait for HSYNC to assert the line should be flagged 802 * as active low so here we are waiting for it to assert 803 */ 804 while (!gpiod_get_value(ts->gpio_hsync)) 805 cpu_relax(); 806 807 /* Then we wait for it do de-assert */ 808 while (gpiod_get_value(ts->gpio_hsync)) 809 cpu_relax(); 810 } 811 812 static void ads7846_read_state(struct ads7846 *ts) 813 { 814 struct ads7846_packet *packet = ts->packet; 815 struct spi_message *m; 816 int msg_idx = 0; 817 int error; 818 819 packet->last_cmd_idx = 0; 820 821 while (true) { 822 ads7846_wait_for_hsync(ts); 823 824 m = &ts->msg[msg_idx]; 825 error = spi_sync(ts->spi, m); 826 if (error) { 827 dev_err_ratelimited(&ts->spi->dev, "spi_sync --> %d\n", error); 828 packet->ignore = true; 829 return; 830 } 831 832 error = ads7846_filter(ts); 833 if (error) 834 continue; 835 836 return; 837 } 838 } 839 840 static void ads7846_report_state(struct ads7846 *ts) 841 { 842 struct ads7846_packet *packet = ts->packet; 843 unsigned int Rt; 844 u16 x, y, z1, z2; 845 846 x = packet->x; 847 y = packet->y; 848 if (ts->model == 7845) { 849 z1 = 0; 850 z2 = 0; 851 } else { 852 z1 = packet->z1; 853 z2 = packet->z2; 854 } 855 856 /* range filtering */ 857 if (x == MAX_12BIT) 858 x = 0; 859 860 if (ts->model == 7843 || ts->model == 7845) { 861 Rt = ts->pressure_max / 2; 862 } else if (likely(x && z1)) { 863 /* compute touch pressure resistance using equation #2 */ 864 Rt = z2; 865 Rt -= z1; 866 Rt *= ts->x_plate_ohms; 867 Rt = DIV_ROUND_CLOSEST(Rt, 16); 868 Rt *= x; 869 Rt /= z1; 870 Rt = DIV_ROUND_CLOSEST(Rt, 256); 871 } else { 872 Rt = 0; 873 } 874 875 /* 876 * Sample found inconsistent by debouncing or pressure is beyond 877 * the maximum. Don't report it to user space, repeat at least 878 * once more the measurement 879 */ 880 if (packet->ignore || Rt > ts->pressure_max) { 881 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 882 packet->ignore, Rt); 883 return; 884 } 885 886 /* 887 * Maybe check the pendown state before reporting. This discards 888 * false readings when the pen is lifted. 889 */ 890 if (ts->penirq_recheck_delay_usecs) { 891 udelay(ts->penirq_recheck_delay_usecs); 892 if (!get_pendown_state(ts)) 893 Rt = 0; 894 } 895 896 /* 897 * NOTE: We can't rely on the pressure to determine the pen down 898 * state, even this controller has a pressure sensor. The pressure 899 * value can fluctuate for quite a while after lifting the pen and 900 * in some cases may not even settle at the expected value. 901 * 902 * The only safe way to check for the pen up condition is in the 903 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 904 */ 905 if (Rt) { 906 struct input_dev *input = ts->input; 907 908 if (!ts->pendown) { 909 input_report_key(input, BTN_TOUCH, 1); 910 ts->pendown = true; 911 dev_vdbg(&ts->spi->dev, "DOWN\n"); 912 } 913 914 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 915 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 916 917 input_sync(input); 918 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 919 } 920 } 921 922 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 923 { 924 struct ads7846 *ts = handle; 925 926 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 927 } 928 929 930 static irqreturn_t ads7846_irq(int irq, void *handle) 931 { 932 struct ads7846 *ts = handle; 933 934 /* Start with a small delay before checking pendown state */ 935 msleep(TS_POLL_DELAY); 936 937 while (!ts->stopped && get_pendown_state(ts)) { 938 939 /* pen is down, continue with the measurement */ 940 ads7846_read_state(ts); 941 942 if (!ts->stopped) 943 ads7846_report_state(ts); 944 945 wait_event_timeout(ts->wait, ts->stopped, 946 msecs_to_jiffies(TS_POLL_PERIOD)); 947 } 948 949 if (ts->pendown && !ts->stopped) 950 ads7846_report_pen_up(ts); 951 952 return IRQ_HANDLED; 953 } 954 955 static int ads7846_suspend(struct device *dev) 956 { 957 struct ads7846 *ts = dev_get_drvdata(dev); 958 959 mutex_lock(&ts->lock); 960 961 if (!ts->suspended) { 962 963 if (!ts->disabled) 964 __ads7846_disable(ts); 965 966 if (device_may_wakeup(&ts->spi->dev)) 967 enable_irq_wake(ts->spi->irq); 968 969 ts->suspended = true; 970 } 971 972 mutex_unlock(&ts->lock); 973 974 return 0; 975 } 976 977 static int ads7846_resume(struct device *dev) 978 { 979 struct ads7846 *ts = dev_get_drvdata(dev); 980 981 mutex_lock(&ts->lock); 982 983 if (ts->suspended) { 984 985 ts->suspended = false; 986 987 if (device_may_wakeup(&ts->spi->dev)) 988 disable_irq_wake(ts->spi->irq); 989 990 if (!ts->disabled) 991 __ads7846_enable(ts); 992 } 993 994 mutex_unlock(&ts->lock); 995 996 return 0; 997 } 998 999 static DEFINE_SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 1000 1001 static int ads7846_setup_pendown(struct spi_device *spi, 1002 struct ads7846 *ts, 1003 const struct ads7846_platform_data *pdata) 1004 { 1005 /* 1006 * REVISIT when the irq can be triggered active-low, or if for some 1007 * reason the touchscreen isn't hooked up, we don't need to access 1008 * the pendown state. 1009 */ 1010 1011 if (pdata->get_pendown_state) { 1012 ts->get_pendown_state = pdata->get_pendown_state; 1013 } else { 1014 ts->gpio_pendown = gpiod_get(&spi->dev, "pendown", GPIOD_IN); 1015 if (IS_ERR(ts->gpio_pendown)) { 1016 dev_err(&spi->dev, "failed to request pendown GPIO\n"); 1017 return PTR_ERR(ts->gpio_pendown); 1018 } 1019 if (pdata->gpio_pendown_debounce) 1020 gpiod_set_debounce(ts->gpio_pendown, 1021 pdata->gpio_pendown_debounce); 1022 } 1023 1024 return 0; 1025 } 1026 1027 /* 1028 * Set up the transfers to read touchscreen state; this assumes we 1029 * use formula #2 for pressure, not #3. 1030 */ 1031 static int ads7846_setup_spi_msg(struct ads7846 *ts, 1032 const struct ads7846_platform_data *pdata) 1033 { 1034 struct spi_message *m = &ts->msg[0]; 1035 struct spi_transfer *x = ts->xfer; 1036 struct ads7846_packet *packet = ts->packet; 1037 int vref = pdata->keep_vref_on; 1038 unsigned int count, offset = 0; 1039 unsigned int cmd_idx, b; 1040 unsigned long time; 1041 size_t size = 0; 1042 1043 /* time per bit */ 1044 time = NSEC_PER_SEC / ts->spi->max_speed_hz; 1045 1046 count = pdata->settle_delay_usecs * NSEC_PER_USEC / time; 1047 packet->count_skip = DIV_ROUND_UP(count, 24); 1048 1049 if (ts->debounce_max && ts->debounce_rep) 1050 /* ads7846_debounce_filter() is making ts->debounce_rep + 2 1051 * reads. So we need to get all samples for normal case. */ 1052 packet->count = ts->debounce_rep + 2; 1053 else 1054 packet->count = 1; 1055 1056 if (ts->model == 7846) 1057 packet->cmds = 5; /* x, y, z1, z2, pwdown */ 1058 else 1059 packet->cmds = 3; /* x, y, pwdown */ 1060 1061 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) { 1062 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 1063 unsigned int max_count; 1064 1065 if (cmd_idx == packet->cmds - 1) 1066 cmd_idx = ADS7846_PWDOWN; 1067 1068 if (ads7846_cmd_need_settle(cmd_idx)) 1069 max_count = packet->count + packet->count_skip; 1070 else 1071 max_count = packet->count; 1072 1073 l->offset = offset; 1074 offset += max_count; 1075 l->count = max_count; 1076 l->skip = packet->count_skip; 1077 size += sizeof(*packet->tx) * max_count; 1078 } 1079 1080 packet->tx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL); 1081 if (!packet->tx) 1082 return -ENOMEM; 1083 1084 packet->rx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL); 1085 if (!packet->rx) 1086 return -ENOMEM; 1087 1088 if (ts->model == 7873) { 1089 /* 1090 * The AD7873 is almost identical to the ADS7846 1091 * keep VREF off during differential/ratiometric 1092 * conversion modes. 1093 */ 1094 ts->model = 7846; 1095 vref = 0; 1096 } 1097 1098 ts->msg_count = 1; 1099 spi_message_init(m); 1100 m->context = ts; 1101 1102 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) { 1103 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 1104 u8 cmd; 1105 1106 if (cmd_idx == packet->cmds - 1) 1107 cmd_idx = ADS7846_PWDOWN; 1108 1109 cmd = ads7846_get_cmd(cmd_idx, vref); 1110 1111 for (b = 0; b < l->count; b++) 1112 packet->tx[l->offset + b].cmd = cmd; 1113 } 1114 1115 x->tx_buf = packet->tx; 1116 x->rx_buf = packet->rx; 1117 x->len = size; 1118 spi_message_add_tail(x, m); 1119 1120 return 0; 1121 } 1122 1123 static const struct of_device_id ads7846_dt_ids[] = { 1124 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1125 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1126 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1127 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1128 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1129 { } 1130 }; 1131 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1132 1133 static const struct spi_device_id ads7846_spi_ids[] = { 1134 { "tsc2046", 7846 }, 1135 { "ads7843", 7843 }, 1136 { "ads7845", 7845 }, 1137 { "ads7846", 7846 }, 1138 { "ads7873", 7873 }, 1139 { }, 1140 }; 1141 MODULE_DEVICE_TABLE(spi, ads7846_spi_ids); 1142 1143 static const struct ads7846_platform_data *ads7846_get_props(struct device *dev) 1144 { 1145 struct ads7846_platform_data *pdata; 1146 u32 value; 1147 1148 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1149 if (!pdata) 1150 return ERR_PTR(-ENOMEM); 1151 1152 pdata->model = (uintptr_t)device_get_match_data(dev); 1153 1154 device_property_read_u16(dev, "ti,vref-delay-usecs", 1155 &pdata->vref_delay_usecs); 1156 device_property_read_u16(dev, "ti,vref-mv", &pdata->vref_mv); 1157 pdata->keep_vref_on = device_property_read_bool(dev, "ti,keep-vref-on"); 1158 1159 pdata->swap_xy = device_property_read_bool(dev, "ti,swap-xy"); 1160 1161 device_property_read_u16(dev, "ti,settle-delay-usec", 1162 &pdata->settle_delay_usecs); 1163 device_property_read_u16(dev, "ti,penirq-recheck-delay-usecs", 1164 &pdata->penirq_recheck_delay_usecs); 1165 1166 device_property_read_u16(dev, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1167 device_property_read_u16(dev, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1168 1169 device_property_read_u16(dev, "ti,x-min", &pdata->x_min); 1170 device_property_read_u16(dev, "ti,y-min", &pdata->y_min); 1171 device_property_read_u16(dev, "ti,x-max", &pdata->x_max); 1172 device_property_read_u16(dev, "ti,y-max", &pdata->y_max); 1173 1174 /* 1175 * touchscreen-max-pressure gets parsed during 1176 * touchscreen_parse_properties() 1177 */ 1178 device_property_read_u16(dev, "ti,pressure-min", &pdata->pressure_min); 1179 if (!device_property_read_u32(dev, "touchscreen-min-pressure", &value)) 1180 pdata->pressure_min = (u16) value; 1181 device_property_read_u16(dev, "ti,pressure-max", &pdata->pressure_max); 1182 1183 device_property_read_u16(dev, "ti,debounce-max", &pdata->debounce_max); 1184 if (!device_property_read_u32(dev, "touchscreen-average-samples", &value)) 1185 pdata->debounce_max = (u16) value; 1186 device_property_read_u16(dev, "ti,debounce-tol", &pdata->debounce_tol); 1187 device_property_read_u16(dev, "ti,debounce-rep", &pdata->debounce_rep); 1188 1189 device_property_read_u32(dev, "ti,pendown-gpio-debounce", 1190 &pdata->gpio_pendown_debounce); 1191 1192 pdata->wakeup = device_property_read_bool(dev, "wakeup-source") || 1193 device_property_read_bool(dev, "linux,wakeup"); 1194 1195 return pdata; 1196 } 1197 1198 static void ads7846_regulator_disable(void *regulator) 1199 { 1200 regulator_disable(regulator); 1201 } 1202 1203 static int ads7846_probe(struct spi_device *spi) 1204 { 1205 const struct ads7846_platform_data *pdata; 1206 struct ads7846 *ts; 1207 struct device *dev = &spi->dev; 1208 struct ads7846_packet *packet; 1209 struct input_dev *input_dev; 1210 unsigned long irq_flags; 1211 int err; 1212 1213 if (!spi->irq) { 1214 dev_dbg(dev, "no IRQ?\n"); 1215 return -EINVAL; 1216 } 1217 1218 /* don't exceed max specified sample rate */ 1219 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1220 dev_err(dev, "f(sample) %d KHz?\n", 1221 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1222 return -EINVAL; 1223 } 1224 1225 /* 1226 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1227 * that even if the hardware can do that, the SPI controller driver 1228 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1229 */ 1230 spi->bits_per_word = 8; 1231 spi->mode &= ~SPI_MODE_X_MASK; 1232 spi->mode |= SPI_MODE_0; 1233 err = spi_setup(spi); 1234 if (err < 0) 1235 return err; 1236 1237 ts = devm_kzalloc(dev, sizeof(struct ads7846), GFP_KERNEL); 1238 if (!ts) 1239 return -ENOMEM; 1240 1241 packet = devm_kzalloc(dev, sizeof(struct ads7846_packet), GFP_KERNEL); 1242 if (!packet) 1243 return -ENOMEM; 1244 1245 input_dev = devm_input_allocate_device(dev); 1246 if (!input_dev) 1247 return -ENOMEM; 1248 1249 spi_set_drvdata(spi, ts); 1250 1251 ts->packet = packet; 1252 ts->spi = spi; 1253 ts->input = input_dev; 1254 1255 mutex_init(&ts->lock); 1256 init_waitqueue_head(&ts->wait); 1257 1258 pdata = dev_get_platdata(dev); 1259 if (!pdata) { 1260 pdata = ads7846_get_props(dev); 1261 if (IS_ERR(pdata)) 1262 return PTR_ERR(pdata); 1263 } 1264 1265 ts->model = pdata->model ? : 7846; 1266 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1267 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1268 ts->vref_mv = pdata->vref_mv; 1269 1270 if (pdata->debounce_max) { 1271 ts->debounce_max = pdata->debounce_max; 1272 if (ts->debounce_max < 2) 1273 ts->debounce_max = 2; 1274 ts->debounce_tol = pdata->debounce_tol; 1275 ts->debounce_rep = pdata->debounce_rep; 1276 ts->filter = ads7846_debounce_filter; 1277 ts->filter_data = ts; 1278 } else { 1279 ts->filter = ads7846_no_filter; 1280 } 1281 1282 err = ads7846_setup_pendown(spi, ts, pdata); 1283 if (err) 1284 return err; 1285 1286 if (pdata->penirq_recheck_delay_usecs) 1287 ts->penirq_recheck_delay_usecs = 1288 pdata->penirq_recheck_delay_usecs; 1289 1290 ts->wait_for_sync = pdata->wait_for_sync; 1291 1292 ts->gpio_hsync = devm_gpiod_get_optional(dev, "ti,hsync", GPIOD_IN); 1293 if (IS_ERR(ts->gpio_hsync)) 1294 return PTR_ERR(ts->gpio_hsync); 1295 1296 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 1297 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1298 1299 input_dev->name = ts->name; 1300 input_dev->phys = ts->phys; 1301 1302 input_dev->id.bustype = BUS_SPI; 1303 input_dev->id.product = pdata->model; 1304 1305 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 1306 input_set_abs_params(input_dev, ABS_X, 1307 pdata->x_min ? : 0, 1308 pdata->x_max ? : MAX_12BIT, 1309 0, 0); 1310 input_set_abs_params(input_dev, ABS_Y, 1311 pdata->y_min ? : 0, 1312 pdata->y_max ? : MAX_12BIT, 1313 0, 0); 1314 if (ts->model != 7845) 1315 input_set_abs_params(input_dev, ABS_PRESSURE, 1316 pdata->pressure_min, pdata->pressure_max, 0, 0); 1317 1318 /* 1319 * Parse common framework properties. Must be done here to ensure the 1320 * correct behaviour in case of using the legacy vendor bindings. The 1321 * general binding value overrides the vendor specific one. 1322 */ 1323 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1324 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1325 1326 /* 1327 * Check if legacy ti,swap-xy binding is used instead of 1328 * touchscreen-swapped-x-y 1329 */ 1330 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1331 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1332 ts->core_prop.swap_x_y = true; 1333 } 1334 1335 ads7846_setup_spi_msg(ts, pdata); 1336 1337 ts->reg = devm_regulator_get(dev, "vcc"); 1338 if (IS_ERR(ts->reg)) { 1339 err = PTR_ERR(ts->reg); 1340 dev_err(dev, "unable to get regulator: %d\n", err); 1341 return err; 1342 } 1343 1344 err = regulator_enable(ts->reg); 1345 if (err) { 1346 dev_err(dev, "unable to enable regulator: %d\n", err); 1347 return err; 1348 } 1349 1350 err = devm_add_action_or_reset(dev, ads7846_regulator_disable, ts->reg); 1351 if (err) 1352 return err; 1353 1354 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1355 irq_flags |= IRQF_ONESHOT; 1356 1357 err = devm_request_threaded_irq(dev, spi->irq, 1358 ads7846_hard_irq, ads7846_irq, 1359 irq_flags, dev->driver->name, ts); 1360 if (err && err != -EPROBE_DEFER && !pdata->irq_flags) { 1361 dev_info(dev, 1362 "trying pin change workaround on irq %d\n", spi->irq); 1363 irq_flags |= IRQF_TRIGGER_RISING; 1364 err = devm_request_threaded_irq(dev, spi->irq, 1365 ads7846_hard_irq, ads7846_irq, 1366 irq_flags, dev->driver->name, 1367 ts); 1368 } 1369 1370 if (err) { 1371 dev_dbg(dev, "irq %d busy?\n", spi->irq); 1372 return err; 1373 } 1374 1375 err = ads784x_hwmon_register(spi, ts); 1376 if (err) 1377 return err; 1378 1379 dev_info(dev, "touchscreen, irq %d\n", spi->irq); 1380 1381 /* 1382 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1383 * the touchscreen, in case it's not connected. 1384 */ 1385 if (ts->model == 7845) 1386 ads7845_read12_ser(dev, PWRDOWN); 1387 else 1388 (void) ads7846_read12_ser(dev, READ_12BIT_SER(vaux)); 1389 1390 err = input_register_device(input_dev); 1391 if (err) 1392 return err; 1393 1394 device_init_wakeup(dev, pdata->wakeup); 1395 1396 /* 1397 * If device does not carry platform data we must have allocated it 1398 * when parsing DT data. 1399 */ 1400 if (!dev_get_platdata(dev)) 1401 devm_kfree(dev, (void *)pdata); 1402 1403 return 0; 1404 } 1405 1406 static void ads7846_remove(struct spi_device *spi) 1407 { 1408 struct ads7846 *ts = spi_get_drvdata(spi); 1409 1410 ads7846_stop(ts); 1411 } 1412 1413 static struct spi_driver ads7846_driver = { 1414 .driver = { 1415 .name = "ads7846", 1416 .dev_groups = ads784x_groups, 1417 .pm = pm_sleep_ptr(&ads7846_pm), 1418 .of_match_table = ads7846_dt_ids, 1419 }, 1420 .probe = ads7846_probe, 1421 .remove = ads7846_remove, 1422 .id_table = ads7846_spi_ids, 1423 }; 1424 1425 module_spi_driver(ads7846_driver); 1426 1427 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1428 MODULE_LICENSE("GPL"); 1429