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