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/unaligned.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 ads7846_buf { 66 u8 cmd; 67 __be16 data; 68 } __packed; 69 70 struct ads7846_buf_layout { 71 unsigned int offset; 72 unsigned int count; 73 unsigned int skip; 74 }; 75 76 /* 77 * We allocate this separately to avoid cache line sharing issues when 78 * driver is used with DMA-based SPI controllers (like atmel_spi) on 79 * systems where main memory is not DMA-coherent (most non-x86 boards). 80 */ 81 struct ads7846_packet { 82 unsigned int count; 83 unsigned int count_skip; 84 unsigned int cmds; 85 unsigned int last_cmd_idx; 86 struct ads7846_buf_layout l[5]; 87 struct ads7846_buf *rx; 88 struct ads7846_buf *tx; 89 90 struct ads7846_buf pwrdown_cmd; 91 92 bool ignore; 93 u16 x, y, z1, z2; 94 }; 95 96 struct ads7846 { 97 struct input_dev *input; 98 char phys[32]; 99 char name[32]; 100 101 struct spi_device *spi; 102 struct regulator *reg; 103 104 u16 model; 105 u16 vref_mv; 106 u16 vref_delay_usecs; 107 u16 x_plate_ohms; 108 u16 pressure_max; 109 110 bool swap_xy; 111 bool use_internal; 112 113 struct ads7846_packet *packet; 114 115 struct spi_transfer xfer[18]; 116 struct spi_message msg[5]; 117 int msg_count; 118 wait_queue_head_t wait; 119 120 bool pendown; 121 122 int read_cnt; 123 int read_rep; 124 int last_read; 125 126 u16 debounce_max; 127 u16 debounce_tol; 128 u16 debounce_rep; 129 130 u16 penirq_recheck_delay_usecs; 131 132 struct touchscreen_properties core_prop; 133 134 struct mutex lock; 135 bool stopped; /* P: lock */ 136 bool disabled; /* P: lock */ 137 bool suspended; /* P: lock */ 138 139 int (*filter)(void *data, int data_idx, int *val); 140 void *filter_data; 141 int (*get_pendown_state)(void); 142 int gpio_pendown; 143 144 void (*wait_for_sync)(void); 145 }; 146 147 enum ads7846_filter { 148 ADS7846_FILTER_OK, 149 ADS7846_FILTER_REPEAT, 150 ADS7846_FILTER_IGNORE, 151 }; 152 153 /* leave chip selected when we're done, for quicker re-select? */ 154 #if 0 155 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 156 #else 157 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 158 #endif 159 160 /*--------------------------------------------------------------------------*/ 161 162 /* The ADS7846 has touchscreen and other sensors. 163 * Earlier ads784x chips are somewhat compatible. 164 */ 165 #define ADS_START (1 << 7) 166 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 167 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 168 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 169 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 170 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 171 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 172 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 173 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 174 #define ADS_8_BIT (1 << 3) 175 #define ADS_12_BIT (0 << 3) 176 #define ADS_SER (1 << 2) /* non-differential */ 177 #define ADS_DFR (0 << 2) /* differential */ 178 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 179 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 180 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 181 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 182 183 #define MAX_12BIT ((1<<12)-1) 184 185 /* leave ADC powered up (disables penirq) between differential samples */ 186 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 187 | ADS_12_BIT | ADS_DFR | \ 188 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 189 190 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 191 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 192 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 193 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 194 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 195 196 /* single-ended samples need to first power up reference voltage; 197 * we leave both ADC and VREF powered 198 */ 199 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 200 | ADS_12_BIT | ADS_SER) 201 202 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 203 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 204 205 /* Order commands in the most optimal way to reduce Vref switching and 206 * settling time: 207 * Measure: X; Vref: X+, X-; IN: Y+ 208 * Measure: Y; Vref: Y+, Y-; IN: X+ 209 * Measure: Z1; Vref: Y+, X-; IN: X+ 210 * Measure: Z2; Vref: Y+, X-; IN: Y- 211 */ 212 enum ads7846_cmds { 213 ADS7846_X, 214 ADS7846_Y, 215 ADS7846_Z1, 216 ADS7846_Z2, 217 ADS7846_PWDOWN, 218 }; 219 220 static int get_pendown_state(struct ads7846 *ts) 221 { 222 if (ts->get_pendown_state) 223 return ts->get_pendown_state(); 224 225 return !gpio_get_value(ts->gpio_pendown); 226 } 227 228 static void ads7846_report_pen_up(struct ads7846 *ts) 229 { 230 struct input_dev *input = ts->input; 231 232 input_report_key(input, BTN_TOUCH, 0); 233 input_report_abs(input, ABS_PRESSURE, 0); 234 input_sync(input); 235 236 ts->pendown = false; 237 dev_vdbg(&ts->spi->dev, "UP\n"); 238 } 239 240 /* Must be called with ts->lock held */ 241 static void ads7846_stop(struct ads7846 *ts) 242 { 243 if (!ts->disabled && !ts->suspended) { 244 /* Signal IRQ thread to stop polling and disable the handler. */ 245 ts->stopped = true; 246 mb(); 247 wake_up(&ts->wait); 248 disable_irq(ts->spi->irq); 249 } 250 } 251 252 /* Must be called with ts->lock held */ 253 static void ads7846_restart(struct ads7846 *ts) 254 { 255 if (!ts->disabled && !ts->suspended) { 256 /* Check if pen was released since last stop */ 257 if (ts->pendown && !get_pendown_state(ts)) 258 ads7846_report_pen_up(ts); 259 260 /* Tell IRQ thread that it may poll the device. */ 261 ts->stopped = false; 262 mb(); 263 enable_irq(ts->spi->irq); 264 } 265 } 266 267 /* Must be called with ts->lock held */ 268 static void __ads7846_disable(struct ads7846 *ts) 269 { 270 ads7846_stop(ts); 271 regulator_disable(ts->reg); 272 273 /* 274 * We know the chip's in low power mode since we always 275 * leave it that way after every request 276 */ 277 } 278 279 /* Must be called with ts->lock held */ 280 static void __ads7846_enable(struct ads7846 *ts) 281 { 282 int error; 283 284 error = regulator_enable(ts->reg); 285 if (error != 0) 286 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 287 288 ads7846_restart(ts); 289 } 290 291 static void ads7846_disable(struct ads7846 *ts) 292 { 293 mutex_lock(&ts->lock); 294 295 if (!ts->disabled) { 296 297 if (!ts->suspended) 298 __ads7846_disable(ts); 299 300 ts->disabled = true; 301 } 302 303 mutex_unlock(&ts->lock); 304 } 305 306 static void ads7846_enable(struct ads7846 *ts) 307 { 308 mutex_lock(&ts->lock); 309 310 if (ts->disabled) { 311 312 ts->disabled = false; 313 314 if (!ts->suspended) 315 __ads7846_enable(ts); 316 } 317 318 mutex_unlock(&ts->lock); 319 } 320 321 /*--------------------------------------------------------------------------*/ 322 323 /* 324 * Non-touchscreen sensors only use single-ended conversions. 325 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 326 * ads7846 lets that pin be unconnected, to use internal vREF. 327 */ 328 329 struct ser_req { 330 u8 ref_on; 331 u8 command; 332 u8 ref_off; 333 u16 scratch; 334 struct spi_message msg; 335 struct spi_transfer xfer[6]; 336 /* 337 * DMA (thus cache coherency maintenance) requires the 338 * transfer buffers to live in their own cache lines. 339 */ 340 __be16 sample ____cacheline_aligned; 341 }; 342 343 struct ads7845_ser_req { 344 u8 command[3]; 345 struct spi_message msg; 346 struct spi_transfer xfer[2]; 347 /* 348 * DMA (thus cache coherency maintenance) requires the 349 * transfer buffers to live in their own cache lines. 350 */ 351 u8 sample[3] ____cacheline_aligned; 352 }; 353 354 static int ads7846_read12_ser(struct device *dev, unsigned command) 355 { 356 struct spi_device *spi = to_spi_device(dev); 357 struct ads7846 *ts = dev_get_drvdata(dev); 358 struct ser_req *req; 359 int status; 360 361 req = kzalloc(sizeof *req, GFP_KERNEL); 362 if (!req) 363 return -ENOMEM; 364 365 spi_message_init(&req->msg); 366 367 /* maybe turn on internal vREF, and let it settle */ 368 if (ts->use_internal) { 369 req->ref_on = REF_ON; 370 req->xfer[0].tx_buf = &req->ref_on; 371 req->xfer[0].len = 1; 372 spi_message_add_tail(&req->xfer[0], &req->msg); 373 374 req->xfer[1].rx_buf = &req->scratch; 375 req->xfer[1].len = 2; 376 377 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 378 req->xfer[1].delay.value = ts->vref_delay_usecs; 379 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 380 spi_message_add_tail(&req->xfer[1], &req->msg); 381 382 /* Enable reference voltage */ 383 command |= ADS_PD10_REF_ON; 384 } 385 386 /* Enable ADC in every case */ 387 command |= ADS_PD10_ADC_ON; 388 389 /* take sample */ 390 req->command = (u8) command; 391 req->xfer[2].tx_buf = &req->command; 392 req->xfer[2].len = 1; 393 spi_message_add_tail(&req->xfer[2], &req->msg); 394 395 req->xfer[3].rx_buf = &req->sample; 396 req->xfer[3].len = 2; 397 spi_message_add_tail(&req->xfer[3], &req->msg); 398 399 /* REVISIT: take a few more samples, and compare ... */ 400 401 /* converter in low power mode & enable PENIRQ */ 402 req->ref_off = PWRDOWN; 403 req->xfer[4].tx_buf = &req->ref_off; 404 req->xfer[4].len = 1; 405 spi_message_add_tail(&req->xfer[4], &req->msg); 406 407 req->xfer[5].rx_buf = &req->scratch; 408 req->xfer[5].len = 2; 409 CS_CHANGE(req->xfer[5]); 410 spi_message_add_tail(&req->xfer[5], &req->msg); 411 412 mutex_lock(&ts->lock); 413 ads7846_stop(ts); 414 status = spi_sync(spi, &req->msg); 415 ads7846_restart(ts); 416 mutex_unlock(&ts->lock); 417 418 if (status == 0) { 419 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 420 status = be16_to_cpu(req->sample); 421 status = status >> 3; 422 status &= 0x0fff; 423 } 424 425 kfree(req); 426 return status; 427 } 428 429 static int ads7845_read12_ser(struct device *dev, unsigned command) 430 { 431 struct spi_device *spi = to_spi_device(dev); 432 struct ads7846 *ts = dev_get_drvdata(dev); 433 struct ads7845_ser_req *req; 434 int status; 435 436 req = kzalloc(sizeof *req, GFP_KERNEL); 437 if (!req) 438 return -ENOMEM; 439 440 spi_message_init(&req->msg); 441 442 req->command[0] = (u8) command; 443 req->xfer[0].tx_buf = req->command; 444 req->xfer[0].rx_buf = req->sample; 445 req->xfer[0].len = 3; 446 spi_message_add_tail(&req->xfer[0], &req->msg); 447 448 mutex_lock(&ts->lock); 449 ads7846_stop(ts); 450 status = spi_sync(spi, &req->msg); 451 ads7846_restart(ts); 452 mutex_unlock(&ts->lock); 453 454 if (status == 0) { 455 /* BE12 value, then padding */ 456 status = get_unaligned_be16(&req->sample[1]); 457 status = status >> 3; 458 status &= 0x0fff; 459 } 460 461 kfree(req); 462 return status; 463 } 464 465 #if IS_ENABLED(CONFIG_HWMON) 466 467 #define SHOW(name, var, adjust) static ssize_t \ 468 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 469 { \ 470 struct ads7846 *ts = dev_get_drvdata(dev); \ 471 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 472 READ_12BIT_SER(var)); \ 473 if (v < 0) \ 474 return v; \ 475 return sprintf(buf, "%u\n", adjust(ts, v)); \ 476 } \ 477 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 478 479 480 /* Sysfs conventions report temperatures in millidegrees Celsius. 481 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 482 * accuracy scheme without calibration data. For now we won't try either; 483 * userspace sees raw sensor values, and must scale/calibrate appropriately. 484 */ 485 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 486 { 487 return v; 488 } 489 490 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 491 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 492 493 494 /* sysfs conventions report voltages in millivolts. We can convert voltages 495 * if we know vREF. userspace may need to scale vAUX to match the board's 496 * external resistors; we assume that vBATT only uses the internal ones. 497 */ 498 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 499 { 500 unsigned retval = v; 501 502 /* external resistors may scale vAUX into 0..vREF */ 503 retval *= ts->vref_mv; 504 retval = retval >> 12; 505 506 return retval; 507 } 508 509 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 510 { 511 unsigned retval = vaux_adjust(ts, v); 512 513 /* ads7846 has a resistor ladder to scale this signal down */ 514 if (ts->model == 7846) 515 retval *= 4; 516 517 return retval; 518 } 519 520 SHOW(in0_input, vaux, vaux_adjust) 521 SHOW(in1_input, vbatt, vbatt_adjust) 522 523 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 524 int index) 525 { 526 struct device *dev = kobj_to_dev(kobj); 527 struct ads7846 *ts = dev_get_drvdata(dev); 528 529 if (ts->model == 7843 && index < 2) /* in0, in1 */ 530 return 0; 531 if (ts->model == 7845 && index != 2) /* in0 */ 532 return 0; 533 534 return attr->mode; 535 } 536 537 static struct attribute *ads7846_attributes[] = { 538 &dev_attr_temp0.attr, /* 0 */ 539 &dev_attr_temp1.attr, /* 1 */ 540 &dev_attr_in0_input.attr, /* 2 */ 541 &dev_attr_in1_input.attr, /* 3 */ 542 NULL, 543 }; 544 545 static const struct attribute_group ads7846_attr_group = { 546 .attrs = ads7846_attributes, 547 .is_visible = ads7846_is_visible, 548 }; 549 __ATTRIBUTE_GROUPS(ads7846_attr); 550 551 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 552 { 553 struct device *hwmon; 554 555 /* hwmon sensors need a reference voltage */ 556 switch (ts->model) { 557 case 7846: 558 if (!ts->vref_mv) { 559 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 560 ts->vref_mv = 2500; 561 ts->use_internal = true; 562 } 563 break; 564 case 7845: 565 case 7843: 566 if (!ts->vref_mv) { 567 dev_warn(&spi->dev, 568 "external vREF for ADS%d not specified\n", 569 ts->model); 570 return 0; 571 } 572 break; 573 } 574 575 hwmon = devm_hwmon_device_register_with_groups(&spi->dev, 576 spi->modalias, ts, 577 ads7846_attr_groups); 578 579 return PTR_ERR_OR_ZERO(hwmon); 580 } 581 582 #else 583 static inline int ads784x_hwmon_register(struct spi_device *spi, 584 struct ads7846 *ts) 585 { 586 return 0; 587 } 588 #endif 589 590 static ssize_t ads7846_pen_down_show(struct device *dev, 591 struct device_attribute *attr, char *buf) 592 { 593 struct ads7846 *ts = dev_get_drvdata(dev); 594 595 return sprintf(buf, "%u\n", ts->pendown); 596 } 597 598 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 599 600 static ssize_t ads7846_disable_show(struct device *dev, 601 struct device_attribute *attr, char *buf) 602 { 603 struct ads7846 *ts = dev_get_drvdata(dev); 604 605 return sprintf(buf, "%u\n", ts->disabled); 606 } 607 608 static ssize_t ads7846_disable_store(struct device *dev, 609 struct device_attribute *attr, 610 const char *buf, size_t count) 611 { 612 struct ads7846 *ts = dev_get_drvdata(dev); 613 unsigned int i; 614 int err; 615 616 err = kstrtouint(buf, 10, &i); 617 if (err) 618 return err; 619 620 if (i) 621 ads7846_disable(ts); 622 else 623 ads7846_enable(ts); 624 625 return count; 626 } 627 628 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 629 630 static struct attribute *ads784x_attributes[] = { 631 &dev_attr_pen_down.attr, 632 &dev_attr_disable.attr, 633 NULL, 634 }; 635 636 static const struct attribute_group ads784x_attr_group = { 637 .attrs = ads784x_attributes, 638 }; 639 640 /*--------------------------------------------------------------------------*/ 641 642 static void null_wait_for_sync(void) 643 { 644 } 645 646 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 647 { 648 struct ads7846 *ts = ads; 649 650 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 651 /* Start over collecting consistent readings. */ 652 ts->read_rep = 0; 653 /* 654 * Repeat it, if this was the first read or the read 655 * wasn't consistent enough. 656 */ 657 if (ts->read_cnt < ts->debounce_max) { 658 ts->last_read = *val; 659 ts->read_cnt++; 660 return ADS7846_FILTER_REPEAT; 661 } else { 662 /* 663 * Maximum number of debouncing reached and still 664 * not enough number of consistent readings. Abort 665 * the whole sample, repeat it in the next sampling 666 * period. 667 */ 668 ts->read_cnt = 0; 669 return ADS7846_FILTER_IGNORE; 670 } 671 } else { 672 if (++ts->read_rep > ts->debounce_rep) { 673 /* 674 * Got a good reading for this coordinate, 675 * go for the next one. 676 */ 677 ts->read_cnt = 0; 678 ts->read_rep = 0; 679 return ADS7846_FILTER_OK; 680 } else { 681 /* Read more values that are consistent. */ 682 ts->read_cnt++; 683 return ADS7846_FILTER_REPEAT; 684 } 685 } 686 } 687 688 static int ads7846_no_filter(void *ads, int data_idx, int *val) 689 { 690 return ADS7846_FILTER_OK; 691 } 692 693 static int ads7846_get_value(struct ads7846_buf *buf) 694 { 695 int value; 696 697 value = be16_to_cpup(&buf->data); 698 699 /* enforce ADC output is 12 bits width */ 700 return (value >> 3) & 0xfff; 701 } 702 703 static void ads7846_set_cmd_val(struct ads7846 *ts, enum ads7846_cmds cmd_idx, 704 u16 val) 705 { 706 struct ads7846_packet *packet = ts->packet; 707 708 switch (cmd_idx) { 709 case ADS7846_Y: 710 packet->y = val; 711 break; 712 case ADS7846_X: 713 packet->x = val; 714 break; 715 case ADS7846_Z1: 716 packet->z1 = val; 717 break; 718 case ADS7846_Z2: 719 packet->z2 = val; 720 break; 721 default: 722 WARN_ON_ONCE(1); 723 } 724 } 725 726 static u8 ads7846_get_cmd(enum ads7846_cmds cmd_idx, int vref) 727 { 728 switch (cmd_idx) { 729 case ADS7846_Y: 730 return READ_Y(vref); 731 case ADS7846_X: 732 return READ_X(vref); 733 734 /* 7846 specific commands */ 735 case ADS7846_Z1: 736 return READ_Z1(vref); 737 case ADS7846_Z2: 738 return READ_Z2(vref); 739 case ADS7846_PWDOWN: 740 return PWRDOWN; 741 default: 742 WARN_ON_ONCE(1); 743 } 744 745 return 0; 746 } 747 748 static bool ads7846_cmd_need_settle(enum ads7846_cmds cmd_idx) 749 { 750 switch (cmd_idx) { 751 case ADS7846_X: 752 case ADS7846_Y: 753 case ADS7846_Z1: 754 case ADS7846_Z2: 755 return true; 756 case ADS7846_PWDOWN: 757 return false; 758 default: 759 WARN_ON_ONCE(1); 760 } 761 762 return false; 763 } 764 765 static int ads7846_filter(struct ads7846 *ts) 766 { 767 struct ads7846_packet *packet = ts->packet; 768 int action; 769 int val; 770 unsigned int cmd_idx, b; 771 772 packet->ignore = false; 773 for (cmd_idx = packet->last_cmd_idx; cmd_idx < packet->cmds - 1; cmd_idx++) { 774 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 775 776 packet->last_cmd_idx = cmd_idx; 777 778 for (b = l->skip; b < l->count; b++) { 779 val = ads7846_get_value(&packet->rx[l->offset + b]); 780 781 action = ts->filter(ts->filter_data, cmd_idx, &val); 782 if (action == ADS7846_FILTER_REPEAT) { 783 if (b == l->count - 1) 784 return -EAGAIN; 785 } else if (action == ADS7846_FILTER_OK) { 786 ads7846_set_cmd_val(ts, cmd_idx, val); 787 break; 788 } else { 789 packet->ignore = true; 790 return 0; 791 } 792 } 793 } 794 795 return 0; 796 } 797 798 static void ads7846_read_state(struct ads7846 *ts) 799 { 800 struct ads7846_packet *packet = ts->packet; 801 struct spi_message *m; 802 int msg_idx = 0; 803 int error; 804 805 packet->last_cmd_idx = 0; 806 807 while (true) { 808 ts->wait_for_sync(); 809 810 m = &ts->msg[msg_idx]; 811 error = spi_sync(ts->spi, m); 812 if (error) { 813 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 814 packet->ignore = true; 815 return; 816 } 817 818 error = ads7846_filter(ts); 819 if (error) 820 continue; 821 822 return; 823 } 824 } 825 826 static void ads7846_report_state(struct ads7846 *ts) 827 { 828 struct ads7846_packet *packet = ts->packet; 829 unsigned int Rt; 830 u16 x, y, z1, z2; 831 832 x = packet->x; 833 y = packet->y; 834 if (ts->model == 7845) { 835 z1 = 0; 836 z2 = 0; 837 } else { 838 z1 = packet->z1; 839 z2 = packet->z2; 840 } 841 842 /* range filtering */ 843 if (x == MAX_12BIT) 844 x = 0; 845 846 if (ts->model == 7843 || ts->model == 7845) { 847 Rt = ts->pressure_max / 2; 848 } else if (likely(x && z1)) { 849 /* compute touch pressure resistance using equation #2 */ 850 Rt = z2; 851 Rt -= z1; 852 Rt *= ts->x_plate_ohms; 853 Rt = DIV_ROUND_CLOSEST(Rt, 16); 854 Rt *= x; 855 Rt /= z1; 856 Rt = DIV_ROUND_CLOSEST(Rt, 256); 857 } else { 858 Rt = 0; 859 } 860 861 /* 862 * Sample found inconsistent by debouncing or pressure is beyond 863 * the maximum. Don't report it to user space, repeat at least 864 * once more the measurement 865 */ 866 if (packet->ignore || Rt > ts->pressure_max) { 867 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 868 packet->ignore, Rt); 869 return; 870 } 871 872 /* 873 * Maybe check the pendown state before reporting. This discards 874 * false readings when the pen is lifted. 875 */ 876 if (ts->penirq_recheck_delay_usecs) { 877 udelay(ts->penirq_recheck_delay_usecs); 878 if (!get_pendown_state(ts)) 879 Rt = 0; 880 } 881 882 /* 883 * NOTE: We can't rely on the pressure to determine the pen down 884 * state, even this controller has a pressure sensor. The pressure 885 * value can fluctuate for quite a while after lifting the pen and 886 * in some cases may not even settle at the expected value. 887 * 888 * The only safe way to check for the pen up condition is in the 889 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 890 */ 891 if (Rt) { 892 struct input_dev *input = ts->input; 893 894 if (!ts->pendown) { 895 input_report_key(input, BTN_TOUCH, 1); 896 ts->pendown = true; 897 dev_vdbg(&ts->spi->dev, "DOWN\n"); 898 } 899 900 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 901 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 902 903 input_sync(input); 904 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 905 } 906 } 907 908 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 909 { 910 struct ads7846 *ts = handle; 911 912 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 913 } 914 915 916 static irqreturn_t ads7846_irq(int irq, void *handle) 917 { 918 struct ads7846 *ts = handle; 919 920 /* Start with a small delay before checking pendown state */ 921 msleep(TS_POLL_DELAY); 922 923 while (!ts->stopped && get_pendown_state(ts)) { 924 925 /* pen is down, continue with the measurement */ 926 ads7846_read_state(ts); 927 928 if (!ts->stopped) 929 ads7846_report_state(ts); 930 931 wait_event_timeout(ts->wait, ts->stopped, 932 msecs_to_jiffies(TS_POLL_PERIOD)); 933 } 934 935 if (ts->pendown && !ts->stopped) 936 ads7846_report_pen_up(ts); 937 938 return IRQ_HANDLED; 939 } 940 941 static int ads7846_suspend(struct device *dev) 942 { 943 struct ads7846 *ts = dev_get_drvdata(dev); 944 945 mutex_lock(&ts->lock); 946 947 if (!ts->suspended) { 948 949 if (!ts->disabled) 950 __ads7846_disable(ts); 951 952 if (device_may_wakeup(&ts->spi->dev)) 953 enable_irq_wake(ts->spi->irq); 954 955 ts->suspended = true; 956 } 957 958 mutex_unlock(&ts->lock); 959 960 return 0; 961 } 962 963 static int ads7846_resume(struct device *dev) 964 { 965 struct ads7846 *ts = dev_get_drvdata(dev); 966 967 mutex_lock(&ts->lock); 968 969 if (ts->suspended) { 970 971 ts->suspended = false; 972 973 if (device_may_wakeup(&ts->spi->dev)) 974 disable_irq_wake(ts->spi->irq); 975 976 if (!ts->disabled) 977 __ads7846_enable(ts); 978 } 979 980 mutex_unlock(&ts->lock); 981 982 return 0; 983 } 984 985 static DEFINE_SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 986 987 static int ads7846_setup_pendown(struct spi_device *spi, 988 struct ads7846 *ts, 989 const struct ads7846_platform_data *pdata) 990 { 991 int err; 992 993 /* 994 * REVISIT when the irq can be triggered active-low, or if for some 995 * reason the touchscreen isn't hooked up, we don't need to access 996 * the pendown state. 997 */ 998 999 if (pdata->get_pendown_state) { 1000 ts->get_pendown_state = pdata->get_pendown_state; 1001 } else if (gpio_is_valid(pdata->gpio_pendown)) { 1002 1003 err = devm_gpio_request_one(&spi->dev, pdata->gpio_pendown, 1004 GPIOF_IN, "ads7846_pendown"); 1005 if (err) { 1006 dev_err(&spi->dev, 1007 "failed to request/setup pendown GPIO%d: %d\n", 1008 pdata->gpio_pendown, err); 1009 return err; 1010 } 1011 1012 ts->gpio_pendown = pdata->gpio_pendown; 1013 1014 if (pdata->gpio_pendown_debounce) 1015 gpio_set_debounce(pdata->gpio_pendown, 1016 pdata->gpio_pendown_debounce); 1017 } else { 1018 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 1019 return -EINVAL; 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 #ifdef CONFIG_OF 1122 static const struct of_device_id ads7846_dt_ids[] = { 1123 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1124 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1125 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1126 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1127 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1128 { } 1129 }; 1130 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1131 1132 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1133 { 1134 struct ads7846_platform_data *pdata; 1135 struct device_node *node = dev->of_node; 1136 const struct of_device_id *match; 1137 u32 value; 1138 1139 if (!node) { 1140 dev_err(dev, "Device does not have associated DT data\n"); 1141 return ERR_PTR(-EINVAL); 1142 } 1143 1144 match = of_match_device(ads7846_dt_ids, dev); 1145 if (!match) { 1146 dev_err(dev, "Unknown device model\n"); 1147 return ERR_PTR(-EINVAL); 1148 } 1149 1150 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1151 if (!pdata) 1152 return ERR_PTR(-ENOMEM); 1153 1154 pdata->model = (unsigned long)match->data; 1155 1156 of_property_read_u16(node, "ti,vref-delay-usecs", 1157 &pdata->vref_delay_usecs); 1158 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1159 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1160 1161 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1162 1163 of_property_read_u16(node, "ti,settle-delay-usec", 1164 &pdata->settle_delay_usecs); 1165 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1166 &pdata->penirq_recheck_delay_usecs); 1167 1168 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1169 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1170 1171 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1172 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1173 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1174 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1175 1176 /* 1177 * touchscreen-max-pressure gets parsed during 1178 * touchscreen_parse_properties() 1179 */ 1180 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1181 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1182 pdata->pressure_min = (u16) value; 1183 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1184 1185 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1186 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1187 pdata->debounce_max = (u16) value; 1188 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1189 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1190 1191 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1192 &pdata->gpio_pendown_debounce); 1193 1194 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1195 of_property_read_bool(node, "linux,wakeup"); 1196 1197 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1198 1199 return pdata; 1200 } 1201 #else 1202 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1203 { 1204 dev_err(dev, "no platform data defined\n"); 1205 return ERR_PTR(-EINVAL); 1206 } 1207 #endif 1208 1209 static void ads7846_regulator_disable(void *regulator) 1210 { 1211 regulator_disable(regulator); 1212 } 1213 1214 static int ads7846_probe(struct spi_device *spi) 1215 { 1216 const struct ads7846_platform_data *pdata; 1217 struct ads7846 *ts; 1218 struct device *dev = &spi->dev; 1219 struct ads7846_packet *packet; 1220 struct input_dev *input_dev; 1221 unsigned long irq_flags; 1222 int err; 1223 1224 if (!spi->irq) { 1225 dev_dbg(dev, "no IRQ?\n"); 1226 return -EINVAL; 1227 } 1228 1229 /* don't exceed max specified sample rate */ 1230 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1231 dev_err(dev, "f(sample) %d KHz?\n", 1232 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1233 return -EINVAL; 1234 } 1235 1236 /* 1237 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1238 * that even if the hardware can do that, the SPI controller driver 1239 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1240 */ 1241 spi->bits_per_word = 8; 1242 spi->mode &= ~SPI_MODE_X_MASK; 1243 spi->mode |= SPI_MODE_0; 1244 err = spi_setup(spi); 1245 if (err < 0) 1246 return err; 1247 1248 ts = devm_kzalloc(dev, sizeof(struct ads7846), GFP_KERNEL); 1249 if (!ts) 1250 return -ENOMEM; 1251 1252 packet = devm_kzalloc(dev, sizeof(struct ads7846_packet), GFP_KERNEL); 1253 if (!packet) 1254 return -ENOMEM; 1255 1256 input_dev = devm_input_allocate_device(dev); 1257 if (!input_dev) 1258 return -ENOMEM; 1259 1260 spi_set_drvdata(spi, ts); 1261 1262 ts->packet = packet; 1263 ts->spi = spi; 1264 ts->input = input_dev; 1265 1266 mutex_init(&ts->lock); 1267 init_waitqueue_head(&ts->wait); 1268 1269 pdata = dev_get_platdata(dev); 1270 if (!pdata) { 1271 pdata = ads7846_probe_dt(dev); 1272 if (IS_ERR(pdata)) 1273 return PTR_ERR(pdata); 1274 } 1275 1276 ts->model = pdata->model ? : 7846; 1277 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1278 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1279 ts->vref_mv = pdata->vref_mv; 1280 1281 if (pdata->debounce_max) { 1282 ts->debounce_max = pdata->debounce_max; 1283 if (ts->debounce_max < 2) 1284 ts->debounce_max = 2; 1285 ts->debounce_tol = pdata->debounce_tol; 1286 ts->debounce_rep = pdata->debounce_rep; 1287 ts->filter = ads7846_debounce_filter; 1288 ts->filter_data = ts; 1289 } else { 1290 ts->filter = ads7846_no_filter; 1291 } 1292 1293 err = ads7846_setup_pendown(spi, ts, pdata); 1294 if (err) 1295 return err; 1296 1297 if (pdata->penirq_recheck_delay_usecs) 1298 ts->penirq_recheck_delay_usecs = 1299 pdata->penirq_recheck_delay_usecs; 1300 1301 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1302 1303 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 1304 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1305 1306 input_dev->name = ts->name; 1307 input_dev->phys = ts->phys; 1308 1309 input_dev->id.bustype = BUS_SPI; 1310 input_dev->id.product = pdata->model; 1311 1312 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 1313 input_set_abs_params(input_dev, ABS_X, 1314 pdata->x_min ? : 0, 1315 pdata->x_max ? : MAX_12BIT, 1316 0, 0); 1317 input_set_abs_params(input_dev, ABS_Y, 1318 pdata->y_min ? : 0, 1319 pdata->y_max ? : MAX_12BIT, 1320 0, 0); 1321 if (ts->model != 7845) 1322 input_set_abs_params(input_dev, ABS_PRESSURE, 1323 pdata->pressure_min, pdata->pressure_max, 0, 0); 1324 1325 /* 1326 * Parse common framework properties. Must be done here to ensure the 1327 * correct behaviour in case of using the legacy vendor bindings. The 1328 * general binding value overrides the vendor specific one. 1329 */ 1330 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1331 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1332 1333 /* 1334 * Check if legacy ti,swap-xy binding is used instead of 1335 * touchscreen-swapped-x-y 1336 */ 1337 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1338 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1339 ts->core_prop.swap_x_y = true; 1340 } 1341 1342 ads7846_setup_spi_msg(ts, pdata); 1343 1344 ts->reg = devm_regulator_get(dev, "vcc"); 1345 if (IS_ERR(ts->reg)) { 1346 err = PTR_ERR(ts->reg); 1347 dev_err(dev, "unable to get regulator: %d\n", err); 1348 return err; 1349 } 1350 1351 err = regulator_enable(ts->reg); 1352 if (err) { 1353 dev_err(dev, "unable to enable regulator: %d\n", err); 1354 return err; 1355 } 1356 1357 err = devm_add_action_or_reset(dev, ads7846_regulator_disable, ts->reg); 1358 if (err) 1359 return err; 1360 1361 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1362 irq_flags |= IRQF_ONESHOT; 1363 1364 err = devm_request_threaded_irq(dev, spi->irq, 1365 ads7846_hard_irq, ads7846_irq, 1366 irq_flags, dev->driver->name, ts); 1367 if (err && err != -EPROBE_DEFER && !pdata->irq_flags) { 1368 dev_info(dev, 1369 "trying pin change workaround on irq %d\n", spi->irq); 1370 irq_flags |= IRQF_TRIGGER_RISING; 1371 err = devm_request_threaded_irq(dev, spi->irq, 1372 ads7846_hard_irq, ads7846_irq, 1373 irq_flags, dev->driver->name, 1374 ts); 1375 } 1376 1377 if (err) { 1378 dev_dbg(dev, "irq %d busy?\n", spi->irq); 1379 return err; 1380 } 1381 1382 err = ads784x_hwmon_register(spi, ts); 1383 if (err) 1384 return err; 1385 1386 dev_info(dev, "touchscreen, irq %d\n", spi->irq); 1387 1388 /* 1389 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1390 * the touchscreen, in case it's not connected. 1391 */ 1392 if (ts->model == 7845) 1393 ads7845_read12_ser(dev, PWRDOWN); 1394 else 1395 (void) ads7846_read12_ser(dev, READ_12BIT_SER(vaux)); 1396 1397 err = devm_device_add_group(dev, &ads784x_attr_group); 1398 if (err) 1399 return err; 1400 1401 err = input_register_device(input_dev); 1402 if (err) 1403 return err; 1404 1405 device_init_wakeup(dev, pdata->wakeup); 1406 1407 /* 1408 * If device does not carry platform data we must have allocated it 1409 * when parsing DT data. 1410 */ 1411 if (!dev_get_platdata(dev)) 1412 devm_kfree(dev, (void *)pdata); 1413 1414 return 0; 1415 } 1416 1417 static void ads7846_remove(struct spi_device *spi) 1418 { 1419 struct ads7846 *ts = spi_get_drvdata(spi); 1420 1421 ads7846_stop(ts); 1422 } 1423 1424 static struct spi_driver ads7846_driver = { 1425 .driver = { 1426 .name = "ads7846", 1427 .pm = pm_sleep_ptr(&ads7846_pm), 1428 .of_match_table = of_match_ptr(ads7846_dt_ids), 1429 }, 1430 .probe = ads7846_probe, 1431 .remove = ads7846_remove, 1432 }; 1433 1434 module_spi_driver(ads7846_driver); 1435 1436 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1437 MODULE_LICENSE("GPL"); 1438 MODULE_ALIAS("spi:ads7846"); 1439