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/interrupt.h> 24 #include <linux/slab.h> 25 #include <linux/pm.h> 26 #include <linux/of.h> 27 #include <linux/of_gpio.h> 28 #include <linux/of_device.h> 29 #include <linux/gpio.h> 30 #include <linux/spi/spi.h> 31 #include <linux/spi/ads7846.h> 32 #include <linux/regulator/consumer.h> 33 #include <linux/module.h> 34 #include <asm/irq.h> 35 36 /* 37 * This code has been heavily tested on a Nokia 770, and lightly 38 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 39 * TSC2046 is just newer ads7846 silicon. 40 * Support for ads7843 tested on Atmel at91sam926x-EK. 41 * Support for ads7845 has only been stubbed in. 42 * Support for Analog Devices AD7873 and AD7843 tested. 43 * 44 * IRQ handling needs a workaround because of a shortcoming in handling 45 * edge triggered IRQs on some platforms like the OMAP1/2. These 46 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 47 * have to maintain our own SW IRQ disabled status. This should be 48 * removed as soon as the affected platform's IRQ handling is fixed. 49 * 50 * App note sbaa036 talks in more detail about accurate sampling... 51 * that ought to help in situations like LCDs inducing noise (which 52 * can also be helped by using synch signals) and more generally. 53 * This driver tries to utilize the measures described in the app 54 * note. The strength of filtering can be set in the board-* specific 55 * files. 56 */ 57 58 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 59 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 60 61 /* this driver doesn't aim at the peak continuous sample rate */ 62 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 63 64 struct ts_event { 65 /* 66 * For portability, we can't read 12 bit values using SPI (which 67 * would make the controller deliver them as native byte order u16 68 * with msbs zeroed). Instead, we read them as two 8-bit values, 69 * *** WHICH NEED BYTESWAPPING *** and range adjustment. 70 */ 71 u16 x; 72 u16 y; 73 u16 z1, z2; 74 bool ignore; 75 u8 x_buf[3]; 76 u8 y_buf[3]; 77 }; 78 79 /* 80 * We allocate this separately to avoid cache line sharing issues when 81 * driver is used with DMA-based SPI controllers (like atmel_spi) on 82 * systems where main memory is not DMA-coherent (most non-x86 boards). 83 */ 84 struct ads7846_packet { 85 u8 read_x, read_y, read_z1, read_z2, pwrdown; 86 u16 dummy; /* for the pwrdown read */ 87 struct ts_event tc; 88 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ 89 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; 90 }; 91 92 struct ads7846 { 93 struct input_dev *input; 94 char phys[32]; 95 char name[32]; 96 97 struct spi_device *spi; 98 struct regulator *reg; 99 100 #if IS_ENABLED(CONFIG_HWMON) 101 struct device *hwmon; 102 #endif 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 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 void (*filter_cleanup)(void *data); 140 int (*get_pendown_state)(void); 141 int gpio_pendown; 142 143 void (*wait_for_sync)(void); 144 }; 145 146 /* leave chip selected when we're done, for quicker re-select? */ 147 #if 0 148 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 149 #else 150 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 151 #endif 152 153 /*--------------------------------------------------------------------------*/ 154 155 /* The ADS7846 has touchscreen and other sensors. 156 * Earlier ads784x chips are somewhat compatible. 157 */ 158 #define ADS_START (1 << 7) 159 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 160 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 161 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 162 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 163 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 164 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 165 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 166 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 167 #define ADS_8_BIT (1 << 3) 168 #define ADS_12_BIT (0 << 3) 169 #define ADS_SER (1 << 2) /* non-differential */ 170 #define ADS_DFR (0 << 2) /* differential */ 171 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 172 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 173 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 174 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 175 176 #define MAX_12BIT ((1<<12)-1) 177 178 /* leave ADC powered up (disables penirq) between differential samples */ 179 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 180 | ADS_12_BIT | ADS_DFR | \ 181 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 182 183 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 184 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 185 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 186 187 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 188 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 189 190 /* single-ended samples need to first power up reference voltage; 191 * we leave both ADC and VREF powered 192 */ 193 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 194 | ADS_12_BIT | ADS_SER) 195 196 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 197 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 198 199 /* Must be called with ts->lock held */ 200 static void ads7846_stop(struct ads7846 *ts) 201 { 202 if (!ts->disabled && !ts->suspended) { 203 /* Signal IRQ thread to stop polling and disable the handler. */ 204 ts->stopped = true; 205 mb(); 206 wake_up(&ts->wait); 207 disable_irq(ts->spi->irq); 208 } 209 } 210 211 /* Must be called with ts->lock held */ 212 static void ads7846_restart(struct ads7846 *ts) 213 { 214 if (!ts->disabled && !ts->suspended) { 215 /* Tell IRQ thread that it may poll the device. */ 216 ts->stopped = false; 217 mb(); 218 enable_irq(ts->spi->irq); 219 } 220 } 221 222 /* Must be called with ts->lock held */ 223 static void __ads7846_disable(struct ads7846 *ts) 224 { 225 ads7846_stop(ts); 226 regulator_disable(ts->reg); 227 228 /* 229 * We know the chip's in low power mode since we always 230 * leave it that way after every request 231 */ 232 } 233 234 /* Must be called with ts->lock held */ 235 static void __ads7846_enable(struct ads7846 *ts) 236 { 237 int error; 238 239 error = regulator_enable(ts->reg); 240 if (error != 0) 241 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 242 243 ads7846_restart(ts); 244 } 245 246 static void ads7846_disable(struct ads7846 *ts) 247 { 248 mutex_lock(&ts->lock); 249 250 if (!ts->disabled) { 251 252 if (!ts->suspended) 253 __ads7846_disable(ts); 254 255 ts->disabled = true; 256 } 257 258 mutex_unlock(&ts->lock); 259 } 260 261 static void ads7846_enable(struct ads7846 *ts) 262 { 263 mutex_lock(&ts->lock); 264 265 if (ts->disabled) { 266 267 ts->disabled = false; 268 269 if (!ts->suspended) 270 __ads7846_enable(ts); 271 } 272 273 mutex_unlock(&ts->lock); 274 } 275 276 /*--------------------------------------------------------------------------*/ 277 278 /* 279 * Non-touchscreen sensors only use single-ended conversions. 280 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 281 * ads7846 lets that pin be unconnected, to use internal vREF. 282 */ 283 284 struct ser_req { 285 u8 ref_on; 286 u8 command; 287 u8 ref_off; 288 u16 scratch; 289 struct spi_message msg; 290 struct spi_transfer xfer[6]; 291 /* 292 * DMA (thus cache coherency maintenance) requires the 293 * transfer buffers to live in their own cache lines. 294 */ 295 __be16 sample ____cacheline_aligned; 296 }; 297 298 struct ads7845_ser_req { 299 u8 command[3]; 300 struct spi_message msg; 301 struct spi_transfer xfer[2]; 302 /* 303 * DMA (thus cache coherency maintenance) requires the 304 * transfer buffers to live in their own cache lines. 305 */ 306 u8 sample[3] ____cacheline_aligned; 307 }; 308 309 static int ads7846_read12_ser(struct device *dev, unsigned command) 310 { 311 struct spi_device *spi = to_spi_device(dev); 312 struct ads7846 *ts = dev_get_drvdata(dev); 313 struct ser_req *req; 314 int status; 315 316 req = kzalloc(sizeof *req, GFP_KERNEL); 317 if (!req) 318 return -ENOMEM; 319 320 spi_message_init(&req->msg); 321 322 /* maybe turn on internal vREF, and let it settle */ 323 if (ts->use_internal) { 324 req->ref_on = REF_ON; 325 req->xfer[0].tx_buf = &req->ref_on; 326 req->xfer[0].len = 1; 327 spi_message_add_tail(&req->xfer[0], &req->msg); 328 329 req->xfer[1].rx_buf = &req->scratch; 330 req->xfer[1].len = 2; 331 332 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 333 req->xfer[1].delay_usecs = ts->vref_delay_usecs; 334 spi_message_add_tail(&req->xfer[1], &req->msg); 335 336 /* Enable reference voltage */ 337 command |= ADS_PD10_REF_ON; 338 } 339 340 /* Enable ADC in every case */ 341 command |= ADS_PD10_ADC_ON; 342 343 /* take sample */ 344 req->command = (u8) command; 345 req->xfer[2].tx_buf = &req->command; 346 req->xfer[2].len = 1; 347 spi_message_add_tail(&req->xfer[2], &req->msg); 348 349 req->xfer[3].rx_buf = &req->sample; 350 req->xfer[3].len = 2; 351 spi_message_add_tail(&req->xfer[3], &req->msg); 352 353 /* REVISIT: take a few more samples, and compare ... */ 354 355 /* converter in low power mode & enable PENIRQ */ 356 req->ref_off = PWRDOWN; 357 req->xfer[4].tx_buf = &req->ref_off; 358 req->xfer[4].len = 1; 359 spi_message_add_tail(&req->xfer[4], &req->msg); 360 361 req->xfer[5].rx_buf = &req->scratch; 362 req->xfer[5].len = 2; 363 CS_CHANGE(req->xfer[5]); 364 spi_message_add_tail(&req->xfer[5], &req->msg); 365 366 mutex_lock(&ts->lock); 367 ads7846_stop(ts); 368 status = spi_sync(spi, &req->msg); 369 ads7846_restart(ts); 370 mutex_unlock(&ts->lock); 371 372 if (status == 0) { 373 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 374 status = be16_to_cpu(req->sample); 375 status = status >> 3; 376 status &= 0x0fff; 377 } 378 379 kfree(req); 380 return status; 381 } 382 383 static int ads7845_read12_ser(struct device *dev, unsigned command) 384 { 385 struct spi_device *spi = to_spi_device(dev); 386 struct ads7846 *ts = dev_get_drvdata(dev); 387 struct ads7845_ser_req *req; 388 int status; 389 390 req = kzalloc(sizeof *req, GFP_KERNEL); 391 if (!req) 392 return -ENOMEM; 393 394 spi_message_init(&req->msg); 395 396 req->command[0] = (u8) command; 397 req->xfer[0].tx_buf = req->command; 398 req->xfer[0].rx_buf = req->sample; 399 req->xfer[0].len = 3; 400 spi_message_add_tail(&req->xfer[0], &req->msg); 401 402 mutex_lock(&ts->lock); 403 ads7846_stop(ts); 404 status = spi_sync(spi, &req->msg); 405 ads7846_restart(ts); 406 mutex_unlock(&ts->lock); 407 408 if (status == 0) { 409 /* BE12 value, then padding */ 410 status = be16_to_cpu(*((u16 *)&req->sample[1])); 411 status = status >> 3; 412 status &= 0x0fff; 413 } 414 415 kfree(req); 416 return status; 417 } 418 419 #if IS_ENABLED(CONFIG_HWMON) 420 421 #define SHOW(name, var, adjust) static ssize_t \ 422 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 423 { \ 424 struct ads7846 *ts = dev_get_drvdata(dev); \ 425 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 426 READ_12BIT_SER(var)); \ 427 if (v < 0) \ 428 return v; \ 429 return sprintf(buf, "%u\n", adjust(ts, v)); \ 430 } \ 431 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 432 433 434 /* Sysfs conventions report temperatures in millidegrees Celsius. 435 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 436 * accuracy scheme without calibration data. For now we won't try either; 437 * userspace sees raw sensor values, and must scale/calibrate appropriately. 438 */ 439 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 440 { 441 return v; 442 } 443 444 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 445 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 446 447 448 /* sysfs conventions report voltages in millivolts. We can convert voltages 449 * if we know vREF. userspace may need to scale vAUX to match the board's 450 * external resistors; we assume that vBATT only uses the internal ones. 451 */ 452 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 453 { 454 unsigned retval = v; 455 456 /* external resistors may scale vAUX into 0..vREF */ 457 retval *= ts->vref_mv; 458 retval = retval >> 12; 459 460 return retval; 461 } 462 463 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 464 { 465 unsigned retval = vaux_adjust(ts, v); 466 467 /* ads7846 has a resistor ladder to scale this signal down */ 468 if (ts->model == 7846) 469 retval *= 4; 470 471 return retval; 472 } 473 474 SHOW(in0_input, vaux, vaux_adjust) 475 SHOW(in1_input, vbatt, vbatt_adjust) 476 477 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 478 int index) 479 { 480 struct device *dev = container_of(kobj, struct device, kobj); 481 struct ads7846 *ts = dev_get_drvdata(dev); 482 483 if (ts->model == 7843 && index < 2) /* in0, in1 */ 484 return 0; 485 if (ts->model == 7845 && index != 2) /* in0 */ 486 return 0; 487 488 return attr->mode; 489 } 490 491 static struct attribute *ads7846_attributes[] = { 492 &dev_attr_temp0.attr, /* 0 */ 493 &dev_attr_temp1.attr, /* 1 */ 494 &dev_attr_in0_input.attr, /* 2 */ 495 &dev_attr_in1_input.attr, /* 3 */ 496 NULL, 497 }; 498 499 static const struct attribute_group ads7846_attr_group = { 500 .attrs = ads7846_attributes, 501 .is_visible = ads7846_is_visible, 502 }; 503 __ATTRIBUTE_GROUPS(ads7846_attr); 504 505 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 506 { 507 /* hwmon sensors need a reference voltage */ 508 switch (ts->model) { 509 case 7846: 510 if (!ts->vref_mv) { 511 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 512 ts->vref_mv = 2500; 513 ts->use_internal = true; 514 } 515 break; 516 case 7845: 517 case 7843: 518 if (!ts->vref_mv) { 519 dev_warn(&spi->dev, 520 "external vREF for ADS%d not specified\n", 521 ts->model); 522 return 0; 523 } 524 break; 525 } 526 527 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 528 ts, ads7846_attr_groups); 529 530 return PTR_ERR_OR_ZERO(ts->hwmon); 531 } 532 533 static void ads784x_hwmon_unregister(struct spi_device *spi, 534 struct ads7846 *ts) 535 { 536 if (ts->hwmon) 537 hwmon_device_unregister(ts->hwmon); 538 } 539 540 #else 541 static inline int ads784x_hwmon_register(struct spi_device *spi, 542 struct ads7846 *ts) 543 { 544 return 0; 545 } 546 547 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 548 struct ads7846 *ts) 549 { 550 } 551 #endif 552 553 static ssize_t ads7846_pen_down_show(struct device *dev, 554 struct device_attribute *attr, char *buf) 555 { 556 struct ads7846 *ts = dev_get_drvdata(dev); 557 558 return sprintf(buf, "%u\n", ts->pendown); 559 } 560 561 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 562 563 static ssize_t ads7846_disable_show(struct device *dev, 564 struct device_attribute *attr, char *buf) 565 { 566 struct ads7846 *ts = dev_get_drvdata(dev); 567 568 return sprintf(buf, "%u\n", ts->disabled); 569 } 570 571 static ssize_t ads7846_disable_store(struct device *dev, 572 struct device_attribute *attr, 573 const char *buf, size_t count) 574 { 575 struct ads7846 *ts = dev_get_drvdata(dev); 576 unsigned int i; 577 int err; 578 579 err = kstrtouint(buf, 10, &i); 580 if (err) 581 return err; 582 583 if (i) 584 ads7846_disable(ts); 585 else 586 ads7846_enable(ts); 587 588 return count; 589 } 590 591 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 592 593 static struct attribute *ads784x_attributes[] = { 594 &dev_attr_pen_down.attr, 595 &dev_attr_disable.attr, 596 NULL, 597 }; 598 599 static const struct attribute_group ads784x_attr_group = { 600 .attrs = ads784x_attributes, 601 }; 602 603 /*--------------------------------------------------------------------------*/ 604 605 static int get_pendown_state(struct ads7846 *ts) 606 { 607 if (ts->get_pendown_state) 608 return ts->get_pendown_state(); 609 610 return !gpio_get_value(ts->gpio_pendown); 611 } 612 613 static void null_wait_for_sync(void) 614 { 615 } 616 617 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 618 { 619 struct ads7846 *ts = ads; 620 621 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 622 /* Start over collecting consistent readings. */ 623 ts->read_rep = 0; 624 /* 625 * Repeat it, if this was the first read or the read 626 * wasn't consistent enough. 627 */ 628 if (ts->read_cnt < ts->debounce_max) { 629 ts->last_read = *val; 630 ts->read_cnt++; 631 return ADS7846_FILTER_REPEAT; 632 } else { 633 /* 634 * Maximum number of debouncing reached and still 635 * not enough number of consistent readings. Abort 636 * the whole sample, repeat it in the next sampling 637 * period. 638 */ 639 ts->read_cnt = 0; 640 return ADS7846_FILTER_IGNORE; 641 } 642 } else { 643 if (++ts->read_rep > ts->debounce_rep) { 644 /* 645 * Got a good reading for this coordinate, 646 * go for the next one. 647 */ 648 ts->read_cnt = 0; 649 ts->read_rep = 0; 650 return ADS7846_FILTER_OK; 651 } else { 652 /* Read more values that are consistent. */ 653 ts->read_cnt++; 654 return ADS7846_FILTER_REPEAT; 655 } 656 } 657 } 658 659 static int ads7846_no_filter(void *ads, int data_idx, int *val) 660 { 661 return ADS7846_FILTER_OK; 662 } 663 664 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 665 { 666 int value; 667 struct spi_transfer *t = 668 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 669 670 if (ts->model == 7845) { 671 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); 672 } else { 673 /* 674 * adjust: on-wire is a must-ignore bit, a BE12 value, then 675 * padding; built from two 8 bit values written msb-first. 676 */ 677 value = be16_to_cpup((__be16 *)t->rx_buf); 678 } 679 680 /* enforce ADC output is 12 bits width */ 681 return (value >> 3) & 0xfff; 682 } 683 684 static void ads7846_update_value(struct spi_message *m, int val) 685 { 686 struct spi_transfer *t = 687 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 688 689 *(u16 *)t->rx_buf = val; 690 } 691 692 static void ads7846_read_state(struct ads7846 *ts) 693 { 694 struct ads7846_packet *packet = ts->packet; 695 struct spi_message *m; 696 int msg_idx = 0; 697 int val; 698 int action; 699 int error; 700 701 while (msg_idx < ts->msg_count) { 702 703 ts->wait_for_sync(); 704 705 m = &ts->msg[msg_idx]; 706 error = spi_sync(ts->spi, m); 707 if (error) { 708 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 709 packet->tc.ignore = true; 710 return; 711 } 712 713 /* 714 * Last message is power down request, no need to convert 715 * or filter the value. 716 */ 717 if (msg_idx < ts->msg_count - 1) { 718 719 val = ads7846_get_value(ts, m); 720 721 action = ts->filter(ts->filter_data, msg_idx, &val); 722 switch (action) { 723 case ADS7846_FILTER_REPEAT: 724 continue; 725 726 case ADS7846_FILTER_IGNORE: 727 packet->tc.ignore = true; 728 msg_idx = ts->msg_count - 1; 729 continue; 730 731 case ADS7846_FILTER_OK: 732 ads7846_update_value(m, val); 733 packet->tc.ignore = false; 734 msg_idx++; 735 break; 736 737 default: 738 BUG(); 739 } 740 } else { 741 msg_idx++; 742 } 743 } 744 } 745 746 static void ads7846_report_state(struct ads7846 *ts) 747 { 748 struct ads7846_packet *packet = ts->packet; 749 unsigned int Rt; 750 u16 x, y, z1, z2; 751 752 /* 753 * ads7846_get_value() does in-place conversion (including byte swap) 754 * from on-the-wire format as part of debouncing to get stable 755 * readings. 756 */ 757 if (ts->model == 7845) { 758 x = *(u16 *)packet->tc.x_buf; 759 y = *(u16 *)packet->tc.y_buf; 760 z1 = 0; 761 z2 = 0; 762 } else { 763 x = packet->tc.x; 764 y = packet->tc.y; 765 z1 = packet->tc.z1; 766 z2 = packet->tc.z2; 767 } 768 769 /* range filtering */ 770 if (x == MAX_12BIT) 771 x = 0; 772 773 if (ts->model == 7843) { 774 Rt = ts->pressure_max / 2; 775 } else if (ts->model == 7845) { 776 if (get_pendown_state(ts)) 777 Rt = ts->pressure_max / 2; 778 else 779 Rt = 0; 780 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 781 } else if (likely(x && z1)) { 782 /* compute touch pressure resistance using equation #2 */ 783 Rt = z2; 784 Rt -= z1; 785 Rt *= x; 786 Rt *= ts->x_plate_ohms; 787 Rt /= z1; 788 Rt = (Rt + 2047) >> 12; 789 } else { 790 Rt = 0; 791 } 792 793 /* 794 * Sample found inconsistent by debouncing or pressure is beyond 795 * the maximum. Don't report it to user space, repeat at least 796 * once more the measurement 797 */ 798 if (packet->tc.ignore || Rt > ts->pressure_max) { 799 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 800 packet->tc.ignore, Rt); 801 return; 802 } 803 804 /* 805 * Maybe check the pendown state before reporting. This discards 806 * false readings when the pen is lifted. 807 */ 808 if (ts->penirq_recheck_delay_usecs) { 809 udelay(ts->penirq_recheck_delay_usecs); 810 if (!get_pendown_state(ts)) 811 Rt = 0; 812 } 813 814 /* 815 * NOTE: We can't rely on the pressure to determine the pen down 816 * state, even this controller has a pressure sensor. The pressure 817 * value can fluctuate for quite a while after lifting the pen and 818 * in some cases may not even settle at the expected value. 819 * 820 * The only safe way to check for the pen up condition is in the 821 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 822 */ 823 if (Rt) { 824 struct input_dev *input = ts->input; 825 826 if (ts->swap_xy) 827 swap(x, y); 828 829 if (!ts->pendown) { 830 input_report_key(input, BTN_TOUCH, 1); 831 ts->pendown = true; 832 dev_vdbg(&ts->spi->dev, "DOWN\n"); 833 } 834 835 input_report_abs(input, ABS_X, x); 836 input_report_abs(input, ABS_Y, y); 837 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 838 839 input_sync(input); 840 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 841 } 842 } 843 844 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 845 { 846 struct ads7846 *ts = handle; 847 848 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 849 } 850 851 852 static irqreturn_t ads7846_irq(int irq, void *handle) 853 { 854 struct ads7846 *ts = handle; 855 856 /* Start with a small delay before checking pendown state */ 857 msleep(TS_POLL_DELAY); 858 859 while (!ts->stopped && get_pendown_state(ts)) { 860 861 /* pen is down, continue with the measurement */ 862 ads7846_read_state(ts); 863 864 if (!ts->stopped) 865 ads7846_report_state(ts); 866 867 wait_event_timeout(ts->wait, ts->stopped, 868 msecs_to_jiffies(TS_POLL_PERIOD)); 869 } 870 871 if (ts->pendown && !ts->stopped) { 872 struct input_dev *input = ts->input; 873 874 input_report_key(input, BTN_TOUCH, 0); 875 input_report_abs(input, ABS_PRESSURE, 0); 876 input_sync(input); 877 878 ts->pendown = false; 879 dev_vdbg(&ts->spi->dev, "UP\n"); 880 } 881 882 return IRQ_HANDLED; 883 } 884 885 static int __maybe_unused ads7846_suspend(struct device *dev) 886 { 887 struct ads7846 *ts = dev_get_drvdata(dev); 888 889 mutex_lock(&ts->lock); 890 891 if (!ts->suspended) { 892 893 if (!ts->disabled) 894 __ads7846_disable(ts); 895 896 if (device_may_wakeup(&ts->spi->dev)) 897 enable_irq_wake(ts->spi->irq); 898 899 ts->suspended = true; 900 } 901 902 mutex_unlock(&ts->lock); 903 904 return 0; 905 } 906 907 static int __maybe_unused ads7846_resume(struct device *dev) 908 { 909 struct ads7846 *ts = dev_get_drvdata(dev); 910 911 mutex_lock(&ts->lock); 912 913 if (ts->suspended) { 914 915 ts->suspended = false; 916 917 if (device_may_wakeup(&ts->spi->dev)) 918 disable_irq_wake(ts->spi->irq); 919 920 if (!ts->disabled) 921 __ads7846_enable(ts); 922 } 923 924 mutex_unlock(&ts->lock); 925 926 return 0; 927 } 928 929 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 930 931 static int ads7846_setup_pendown(struct spi_device *spi, 932 struct ads7846 *ts, 933 const struct ads7846_platform_data *pdata) 934 { 935 int err; 936 937 /* 938 * REVISIT when the irq can be triggered active-low, or if for some 939 * reason the touchscreen isn't hooked up, we don't need to access 940 * the pendown state. 941 */ 942 943 if (pdata->get_pendown_state) { 944 ts->get_pendown_state = pdata->get_pendown_state; 945 } else if (gpio_is_valid(pdata->gpio_pendown)) { 946 947 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 948 "ads7846_pendown"); 949 if (err) { 950 dev_err(&spi->dev, 951 "failed to request/setup pendown GPIO%d: %d\n", 952 pdata->gpio_pendown, err); 953 return err; 954 } 955 956 ts->gpio_pendown = pdata->gpio_pendown; 957 958 if (pdata->gpio_pendown_debounce) 959 gpio_set_debounce(pdata->gpio_pendown, 960 pdata->gpio_pendown_debounce); 961 } else { 962 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 963 return -EINVAL; 964 } 965 966 return 0; 967 } 968 969 /* 970 * Set up the transfers to read touchscreen state; this assumes we 971 * use formula #2 for pressure, not #3. 972 */ 973 static void ads7846_setup_spi_msg(struct ads7846 *ts, 974 const struct ads7846_platform_data *pdata) 975 { 976 struct spi_message *m = &ts->msg[0]; 977 struct spi_transfer *x = ts->xfer; 978 struct ads7846_packet *packet = ts->packet; 979 int vref = pdata->keep_vref_on; 980 981 if (ts->model == 7873) { 982 /* 983 * The AD7873 is almost identical to the ADS7846 984 * keep VREF off during differential/ratiometric 985 * conversion modes. 986 */ 987 ts->model = 7846; 988 vref = 0; 989 } 990 991 ts->msg_count = 1; 992 spi_message_init(m); 993 m->context = ts; 994 995 if (ts->model == 7845) { 996 packet->read_y_cmd[0] = READ_Y(vref); 997 packet->read_y_cmd[1] = 0; 998 packet->read_y_cmd[2] = 0; 999 x->tx_buf = &packet->read_y_cmd[0]; 1000 x->rx_buf = &packet->tc.y_buf[0]; 1001 x->len = 3; 1002 spi_message_add_tail(x, m); 1003 } else { 1004 /* y- still on; turn on only y+ (and ADC) */ 1005 packet->read_y = READ_Y(vref); 1006 x->tx_buf = &packet->read_y; 1007 x->len = 1; 1008 spi_message_add_tail(x, m); 1009 1010 x++; 1011 x->rx_buf = &packet->tc.y; 1012 x->len = 2; 1013 spi_message_add_tail(x, m); 1014 } 1015 1016 /* 1017 * The first sample after switching drivers can be low quality; 1018 * optionally discard it, using a second one after the signals 1019 * have had enough time to stabilize. 1020 */ 1021 if (pdata->settle_delay_usecs) { 1022 x->delay_usecs = pdata->settle_delay_usecs; 1023 1024 x++; 1025 x->tx_buf = &packet->read_y; 1026 x->len = 1; 1027 spi_message_add_tail(x, m); 1028 1029 x++; 1030 x->rx_buf = &packet->tc.y; 1031 x->len = 2; 1032 spi_message_add_tail(x, m); 1033 } 1034 1035 ts->msg_count++; 1036 m++; 1037 spi_message_init(m); 1038 m->context = ts; 1039 1040 if (ts->model == 7845) { 1041 x++; 1042 packet->read_x_cmd[0] = READ_X(vref); 1043 packet->read_x_cmd[1] = 0; 1044 packet->read_x_cmd[2] = 0; 1045 x->tx_buf = &packet->read_x_cmd[0]; 1046 x->rx_buf = &packet->tc.x_buf[0]; 1047 x->len = 3; 1048 spi_message_add_tail(x, m); 1049 } else { 1050 /* turn y- off, x+ on, then leave in lowpower */ 1051 x++; 1052 packet->read_x = READ_X(vref); 1053 x->tx_buf = &packet->read_x; 1054 x->len = 1; 1055 spi_message_add_tail(x, m); 1056 1057 x++; 1058 x->rx_buf = &packet->tc.x; 1059 x->len = 2; 1060 spi_message_add_tail(x, m); 1061 } 1062 1063 /* ... maybe discard first sample ... */ 1064 if (pdata->settle_delay_usecs) { 1065 x->delay_usecs = pdata->settle_delay_usecs; 1066 1067 x++; 1068 x->tx_buf = &packet->read_x; 1069 x->len = 1; 1070 spi_message_add_tail(x, m); 1071 1072 x++; 1073 x->rx_buf = &packet->tc.x; 1074 x->len = 2; 1075 spi_message_add_tail(x, m); 1076 } 1077 1078 /* turn y+ off, x- on; we'll use formula #2 */ 1079 if (ts->model == 7846) { 1080 ts->msg_count++; 1081 m++; 1082 spi_message_init(m); 1083 m->context = ts; 1084 1085 x++; 1086 packet->read_z1 = READ_Z1(vref); 1087 x->tx_buf = &packet->read_z1; 1088 x->len = 1; 1089 spi_message_add_tail(x, m); 1090 1091 x++; 1092 x->rx_buf = &packet->tc.z1; 1093 x->len = 2; 1094 spi_message_add_tail(x, m); 1095 1096 /* ... maybe discard first sample ... */ 1097 if (pdata->settle_delay_usecs) { 1098 x->delay_usecs = pdata->settle_delay_usecs; 1099 1100 x++; 1101 x->tx_buf = &packet->read_z1; 1102 x->len = 1; 1103 spi_message_add_tail(x, m); 1104 1105 x++; 1106 x->rx_buf = &packet->tc.z1; 1107 x->len = 2; 1108 spi_message_add_tail(x, m); 1109 } 1110 1111 ts->msg_count++; 1112 m++; 1113 spi_message_init(m); 1114 m->context = ts; 1115 1116 x++; 1117 packet->read_z2 = READ_Z2(vref); 1118 x->tx_buf = &packet->read_z2; 1119 x->len = 1; 1120 spi_message_add_tail(x, m); 1121 1122 x++; 1123 x->rx_buf = &packet->tc.z2; 1124 x->len = 2; 1125 spi_message_add_tail(x, m); 1126 1127 /* ... maybe discard first sample ... */ 1128 if (pdata->settle_delay_usecs) { 1129 x->delay_usecs = pdata->settle_delay_usecs; 1130 1131 x++; 1132 x->tx_buf = &packet->read_z2; 1133 x->len = 1; 1134 spi_message_add_tail(x, m); 1135 1136 x++; 1137 x->rx_buf = &packet->tc.z2; 1138 x->len = 2; 1139 spi_message_add_tail(x, m); 1140 } 1141 } 1142 1143 /* power down */ 1144 ts->msg_count++; 1145 m++; 1146 spi_message_init(m); 1147 m->context = ts; 1148 1149 if (ts->model == 7845) { 1150 x++; 1151 packet->pwrdown_cmd[0] = PWRDOWN; 1152 packet->pwrdown_cmd[1] = 0; 1153 packet->pwrdown_cmd[2] = 0; 1154 x->tx_buf = &packet->pwrdown_cmd[0]; 1155 x->len = 3; 1156 } else { 1157 x++; 1158 packet->pwrdown = PWRDOWN; 1159 x->tx_buf = &packet->pwrdown; 1160 x->len = 1; 1161 spi_message_add_tail(x, m); 1162 1163 x++; 1164 x->rx_buf = &packet->dummy; 1165 x->len = 2; 1166 } 1167 1168 CS_CHANGE(*x); 1169 spi_message_add_tail(x, m); 1170 } 1171 1172 #ifdef CONFIG_OF 1173 static const struct of_device_id ads7846_dt_ids[] = { 1174 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1175 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1176 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1177 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1178 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1179 { } 1180 }; 1181 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1182 1183 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1184 { 1185 struct ads7846_platform_data *pdata; 1186 struct device_node *node = dev->of_node; 1187 const struct of_device_id *match; 1188 1189 if (!node) { 1190 dev_err(dev, "Device does not have associated DT data\n"); 1191 return ERR_PTR(-EINVAL); 1192 } 1193 1194 match = of_match_device(ads7846_dt_ids, dev); 1195 if (!match) { 1196 dev_err(dev, "Unknown device model\n"); 1197 return ERR_PTR(-EINVAL); 1198 } 1199 1200 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1201 if (!pdata) 1202 return ERR_PTR(-ENOMEM); 1203 1204 pdata->model = (unsigned long)match->data; 1205 1206 of_property_read_u16(node, "ti,vref-delay-usecs", 1207 &pdata->vref_delay_usecs); 1208 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1209 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1210 1211 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1212 1213 of_property_read_u16(node, "ti,settle-delay-usec", 1214 &pdata->settle_delay_usecs); 1215 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1216 &pdata->penirq_recheck_delay_usecs); 1217 1218 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1219 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1220 1221 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1222 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1223 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1224 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1225 1226 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1227 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1228 1229 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1230 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1231 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1232 1233 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1234 &pdata->gpio_pendown_debounce); 1235 1236 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1237 of_property_read_bool(node, "linux,wakeup"); 1238 1239 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1240 1241 return pdata; 1242 } 1243 #else 1244 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1245 { 1246 dev_err(dev, "no platform data defined\n"); 1247 return ERR_PTR(-EINVAL); 1248 } 1249 #endif 1250 1251 static int ads7846_probe(struct spi_device *spi) 1252 { 1253 const struct ads7846_platform_data *pdata; 1254 struct ads7846 *ts; 1255 struct ads7846_packet *packet; 1256 struct input_dev *input_dev; 1257 unsigned long irq_flags; 1258 int err; 1259 1260 if (!spi->irq) { 1261 dev_dbg(&spi->dev, "no IRQ?\n"); 1262 return -EINVAL; 1263 } 1264 1265 /* don't exceed max specified sample rate */ 1266 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1267 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1268 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1269 return -EINVAL; 1270 } 1271 1272 /* 1273 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1274 * that even if the hardware can do that, the SPI controller driver 1275 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1276 */ 1277 spi->bits_per_word = 8; 1278 spi->mode = SPI_MODE_0; 1279 err = spi_setup(spi); 1280 if (err < 0) 1281 return err; 1282 1283 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1284 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1285 input_dev = input_allocate_device(); 1286 if (!ts || !packet || !input_dev) { 1287 err = -ENOMEM; 1288 goto err_free_mem; 1289 } 1290 1291 spi_set_drvdata(spi, ts); 1292 1293 ts->packet = packet; 1294 ts->spi = spi; 1295 ts->input = input_dev; 1296 1297 mutex_init(&ts->lock); 1298 init_waitqueue_head(&ts->wait); 1299 1300 pdata = dev_get_platdata(&spi->dev); 1301 if (!pdata) { 1302 pdata = ads7846_probe_dt(&spi->dev); 1303 if (IS_ERR(pdata)) { 1304 err = PTR_ERR(pdata); 1305 goto err_free_mem; 1306 } 1307 } 1308 1309 ts->model = pdata->model ? : 7846; 1310 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1311 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1312 ts->pressure_max = pdata->pressure_max ? : ~0; 1313 1314 ts->vref_mv = pdata->vref_mv; 1315 ts->swap_xy = pdata->swap_xy; 1316 1317 if (pdata->filter != NULL) { 1318 if (pdata->filter_init != NULL) { 1319 err = pdata->filter_init(pdata, &ts->filter_data); 1320 if (err < 0) 1321 goto err_free_mem; 1322 } 1323 ts->filter = pdata->filter; 1324 ts->filter_cleanup = pdata->filter_cleanup; 1325 } else if (pdata->debounce_max) { 1326 ts->debounce_max = pdata->debounce_max; 1327 if (ts->debounce_max < 2) 1328 ts->debounce_max = 2; 1329 ts->debounce_tol = pdata->debounce_tol; 1330 ts->debounce_rep = pdata->debounce_rep; 1331 ts->filter = ads7846_debounce_filter; 1332 ts->filter_data = ts; 1333 } else { 1334 ts->filter = ads7846_no_filter; 1335 } 1336 1337 err = ads7846_setup_pendown(spi, ts, pdata); 1338 if (err) 1339 goto err_cleanup_filter; 1340 1341 if (pdata->penirq_recheck_delay_usecs) 1342 ts->penirq_recheck_delay_usecs = 1343 pdata->penirq_recheck_delay_usecs; 1344 1345 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1346 1347 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1348 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1349 1350 input_dev->name = ts->name; 1351 input_dev->phys = ts->phys; 1352 input_dev->dev.parent = &spi->dev; 1353 1354 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1355 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1356 input_set_abs_params(input_dev, ABS_X, 1357 pdata->x_min ? : 0, 1358 pdata->x_max ? : MAX_12BIT, 1359 0, 0); 1360 input_set_abs_params(input_dev, ABS_Y, 1361 pdata->y_min ? : 0, 1362 pdata->y_max ? : MAX_12BIT, 1363 0, 0); 1364 input_set_abs_params(input_dev, ABS_PRESSURE, 1365 pdata->pressure_min, pdata->pressure_max, 0, 0); 1366 1367 ads7846_setup_spi_msg(ts, pdata); 1368 1369 ts->reg = regulator_get(&spi->dev, "vcc"); 1370 if (IS_ERR(ts->reg)) { 1371 err = PTR_ERR(ts->reg); 1372 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1373 goto err_free_gpio; 1374 } 1375 1376 err = regulator_enable(ts->reg); 1377 if (err) { 1378 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1379 goto err_put_regulator; 1380 } 1381 1382 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1383 irq_flags |= IRQF_ONESHOT; 1384 1385 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1386 irq_flags, spi->dev.driver->name, ts); 1387 if (err && !pdata->irq_flags) { 1388 dev_info(&spi->dev, 1389 "trying pin change workaround on irq %d\n", spi->irq); 1390 irq_flags |= IRQF_TRIGGER_RISING; 1391 err = request_threaded_irq(spi->irq, 1392 ads7846_hard_irq, ads7846_irq, 1393 irq_flags, spi->dev.driver->name, ts); 1394 } 1395 1396 if (err) { 1397 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1398 goto err_disable_regulator; 1399 } 1400 1401 err = ads784x_hwmon_register(spi, ts); 1402 if (err) 1403 goto err_free_irq; 1404 1405 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1406 1407 /* 1408 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1409 * the touchscreen, in case it's not connected. 1410 */ 1411 if (ts->model == 7845) 1412 ads7845_read12_ser(&spi->dev, PWRDOWN); 1413 else 1414 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1415 1416 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1417 if (err) 1418 goto err_remove_hwmon; 1419 1420 err = input_register_device(input_dev); 1421 if (err) 1422 goto err_remove_attr_group; 1423 1424 device_init_wakeup(&spi->dev, pdata->wakeup); 1425 1426 /* 1427 * If device does not carry platform data we must have allocated it 1428 * when parsing DT data. 1429 */ 1430 if (!dev_get_platdata(&spi->dev)) 1431 devm_kfree(&spi->dev, (void *)pdata); 1432 1433 return 0; 1434 1435 err_remove_attr_group: 1436 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1437 err_remove_hwmon: 1438 ads784x_hwmon_unregister(spi, ts); 1439 err_free_irq: 1440 free_irq(spi->irq, ts); 1441 err_disable_regulator: 1442 regulator_disable(ts->reg); 1443 err_put_regulator: 1444 regulator_put(ts->reg); 1445 err_free_gpio: 1446 if (!ts->get_pendown_state) 1447 gpio_free(ts->gpio_pendown); 1448 err_cleanup_filter: 1449 if (ts->filter_cleanup) 1450 ts->filter_cleanup(ts->filter_data); 1451 err_free_mem: 1452 input_free_device(input_dev); 1453 kfree(packet); 1454 kfree(ts); 1455 return err; 1456 } 1457 1458 static int ads7846_remove(struct spi_device *spi) 1459 { 1460 struct ads7846 *ts = spi_get_drvdata(spi); 1461 1462 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1463 1464 ads7846_disable(ts); 1465 free_irq(ts->spi->irq, ts); 1466 1467 input_unregister_device(ts->input); 1468 1469 ads784x_hwmon_unregister(spi, ts); 1470 1471 regulator_put(ts->reg); 1472 1473 if (!ts->get_pendown_state) { 1474 /* 1475 * If we are not using specialized pendown method we must 1476 * have been relying on gpio we set up ourselves. 1477 */ 1478 gpio_free(ts->gpio_pendown); 1479 } 1480 1481 if (ts->filter_cleanup) 1482 ts->filter_cleanup(ts->filter_data); 1483 1484 kfree(ts->packet); 1485 kfree(ts); 1486 1487 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1488 1489 return 0; 1490 } 1491 1492 static struct spi_driver ads7846_driver = { 1493 .driver = { 1494 .name = "ads7846", 1495 .pm = &ads7846_pm, 1496 .of_match_table = of_match_ptr(ads7846_dt_ids), 1497 }, 1498 .probe = ads7846_probe, 1499 .remove = ads7846_remove, 1500 }; 1501 1502 module_spi_driver(ads7846_driver); 1503 1504 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1505 MODULE_LICENSE("GPL"); 1506 MODULE_ALIAS("spi:ads7846"); 1507