1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ADS7846 based touchscreen and sensor driver 4 * 5 * Copyright (c) 2005 David Brownell 6 * Copyright (c) 2006 Nokia Corporation 7 * Various changes: Imre Deak <imre.deak@nokia.com> 8 * 9 * Using code from: 10 * - corgi_ts.c 11 * Copyright (C) 2004-2005 Richard Purdie 12 * - omap_ts.[hc], ads7846.h, ts_osk.c 13 * Copyright (C) 2002 MontaVista Software 14 * Copyright (C) 2004 Texas Instruments 15 * Copyright (C) 2005 Dirk Behme 16 */ 17 #include <linux/types.h> 18 #include <linux/hwmon.h> 19 #include <linux/err.h> 20 #include <linux/sched.h> 21 #include <linux/delay.h> 22 #include <linux/input.h> 23 #include <linux/input/touchscreen.h> 24 #include <linux/interrupt.h> 25 #include <linux/slab.h> 26 #include <linux/pm.h> 27 #include <linux/of.h> 28 #include <linux/of_gpio.h> 29 #include <linux/of_device.h> 30 #include <linux/gpio.h> 31 #include <linux/spi/spi.h> 32 #include <linux/spi/ads7846.h> 33 #include <linux/regulator/consumer.h> 34 #include <linux/module.h> 35 #include <asm/irq.h> 36 37 /* 38 * This code has been heavily tested on a Nokia 770, and lightly 39 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 40 * TSC2046 is just newer ads7846 silicon. 41 * Support for ads7843 tested on Atmel at91sam926x-EK. 42 * Support for ads7845 has only been stubbed in. 43 * Support for Analog Devices AD7873 and AD7843 tested. 44 * 45 * IRQ handling needs a workaround because of a shortcoming in handling 46 * edge triggered IRQs on some platforms like the OMAP1/2. These 47 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 48 * have to maintain our own SW IRQ disabled status. This should be 49 * removed as soon as the affected platform's IRQ handling is fixed. 50 * 51 * App note sbaa036 talks in more detail about accurate sampling... 52 * that ought to help in situations like LCDs inducing noise (which 53 * can also be helped by using synch signals) and more generally. 54 * This driver tries to utilize the measures described in the app 55 * note. The strength of filtering can be set in the board-* specific 56 * files. 57 */ 58 59 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 60 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 61 62 /* this driver doesn't aim at the peak continuous sample rate */ 63 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 64 65 struct ts_event { 66 /* 67 * For portability, we can't read 12 bit values using SPI (which 68 * would make the controller deliver them as native byte order u16 69 * with msbs zeroed). Instead, we read them as two 8-bit values, 70 * *** WHICH NEED BYTESWAPPING *** and range adjustment. 71 */ 72 u16 x; 73 u16 y; 74 u16 z1, z2; 75 bool ignore; 76 u8 x_buf[3]; 77 u8 y_buf[3]; 78 }; 79 80 /* 81 * We allocate this separately to avoid cache line sharing issues when 82 * driver is used with DMA-based SPI controllers (like atmel_spi) on 83 * systems where main memory is not DMA-coherent (most non-x86 boards). 84 */ 85 struct ads7846_packet { 86 u8 read_x, read_y, read_z1, read_z2, pwrdown; 87 u16 dummy; /* for the pwrdown read */ 88 struct ts_event tc; 89 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ 90 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; 91 }; 92 93 struct ads7846 { 94 struct input_dev *input; 95 char phys[32]; 96 char name[32]; 97 98 struct spi_device *spi; 99 struct regulator *reg; 100 101 #if IS_ENABLED(CONFIG_HWMON) 102 struct device *hwmon; 103 #endif 104 105 u16 model; 106 u16 vref_mv; 107 u16 vref_delay_usecs; 108 u16 x_plate_ohms; 109 u16 pressure_max; 110 111 bool swap_xy; 112 bool use_internal; 113 114 struct ads7846_packet *packet; 115 116 struct spi_transfer xfer[18]; 117 struct spi_message msg[5]; 118 int msg_count; 119 wait_queue_head_t wait; 120 121 bool pendown; 122 123 int read_cnt; 124 int read_rep; 125 int last_read; 126 127 u16 debounce_max; 128 u16 debounce_tol; 129 u16 debounce_rep; 130 131 u16 penirq_recheck_delay_usecs; 132 133 struct touchscreen_properties core_prop; 134 135 struct mutex lock; 136 bool stopped; /* P: lock */ 137 bool disabled; /* P: lock */ 138 bool suspended; /* P: lock */ 139 140 int (*filter)(void *data, int data_idx, int *val); 141 void *filter_data; 142 void (*filter_cleanup)(void *data); 143 int (*get_pendown_state)(void); 144 int gpio_pendown; 145 146 void (*wait_for_sync)(void); 147 }; 148 149 /* leave chip selected when we're done, for quicker re-select? */ 150 #if 0 151 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 152 #else 153 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 154 #endif 155 156 /*--------------------------------------------------------------------------*/ 157 158 /* The ADS7846 has touchscreen and other sensors. 159 * Earlier ads784x chips are somewhat compatible. 160 */ 161 #define ADS_START (1 << 7) 162 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 163 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 164 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 165 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 166 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 167 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 168 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 169 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 170 #define ADS_8_BIT (1 << 3) 171 #define ADS_12_BIT (0 << 3) 172 #define ADS_SER (1 << 2) /* non-differential */ 173 #define ADS_DFR (0 << 2) /* differential */ 174 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 175 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 176 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 177 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 178 179 #define MAX_12BIT ((1<<12)-1) 180 181 /* leave ADC powered up (disables penirq) between differential samples */ 182 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 183 | ADS_12_BIT | ADS_DFR | \ 184 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 185 186 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 187 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 188 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 189 190 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 191 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 192 193 /* single-ended samples need to first power up reference voltage; 194 * we leave both ADC and VREF powered 195 */ 196 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 197 | ADS_12_BIT | ADS_SER) 198 199 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 200 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 201 202 /* Must be called with ts->lock held */ 203 static void ads7846_stop(struct ads7846 *ts) 204 { 205 if (!ts->disabled && !ts->suspended) { 206 /* Signal IRQ thread to stop polling and disable the handler. */ 207 ts->stopped = true; 208 mb(); 209 wake_up(&ts->wait); 210 disable_irq(ts->spi->irq); 211 } 212 } 213 214 /* Must be called with ts->lock held */ 215 static void ads7846_restart(struct ads7846 *ts) 216 { 217 if (!ts->disabled && !ts->suspended) { 218 /* Tell IRQ thread that it may poll the device. */ 219 ts->stopped = false; 220 mb(); 221 enable_irq(ts->spi->irq); 222 } 223 } 224 225 /* Must be called with ts->lock held */ 226 static void __ads7846_disable(struct ads7846 *ts) 227 { 228 ads7846_stop(ts); 229 regulator_disable(ts->reg); 230 231 /* 232 * We know the chip's in low power mode since we always 233 * leave it that way after every request 234 */ 235 } 236 237 /* Must be called with ts->lock held */ 238 static void __ads7846_enable(struct ads7846 *ts) 239 { 240 int error; 241 242 error = regulator_enable(ts->reg); 243 if (error != 0) 244 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 245 246 ads7846_restart(ts); 247 } 248 249 static void ads7846_disable(struct ads7846 *ts) 250 { 251 mutex_lock(&ts->lock); 252 253 if (!ts->disabled) { 254 255 if (!ts->suspended) 256 __ads7846_disable(ts); 257 258 ts->disabled = true; 259 } 260 261 mutex_unlock(&ts->lock); 262 } 263 264 static void ads7846_enable(struct ads7846 *ts) 265 { 266 mutex_lock(&ts->lock); 267 268 if (ts->disabled) { 269 270 ts->disabled = false; 271 272 if (!ts->suspended) 273 __ads7846_enable(ts); 274 } 275 276 mutex_unlock(&ts->lock); 277 } 278 279 /*--------------------------------------------------------------------------*/ 280 281 /* 282 * Non-touchscreen sensors only use single-ended conversions. 283 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 284 * ads7846 lets that pin be unconnected, to use internal vREF. 285 */ 286 287 struct ser_req { 288 u8 ref_on; 289 u8 command; 290 u8 ref_off; 291 u16 scratch; 292 struct spi_message msg; 293 struct spi_transfer xfer[6]; 294 /* 295 * DMA (thus cache coherency maintenance) requires the 296 * transfer buffers to live in their own cache lines. 297 */ 298 __be16 sample ____cacheline_aligned; 299 }; 300 301 struct ads7845_ser_req { 302 u8 command[3]; 303 struct spi_message msg; 304 struct spi_transfer xfer[2]; 305 /* 306 * DMA (thus cache coherency maintenance) requires the 307 * transfer buffers to live in their own cache lines. 308 */ 309 u8 sample[3] ____cacheline_aligned; 310 }; 311 312 static int ads7846_read12_ser(struct device *dev, unsigned command) 313 { 314 struct spi_device *spi = to_spi_device(dev); 315 struct ads7846 *ts = dev_get_drvdata(dev); 316 struct ser_req *req; 317 int status; 318 319 req = kzalloc(sizeof *req, GFP_KERNEL); 320 if (!req) 321 return -ENOMEM; 322 323 spi_message_init(&req->msg); 324 325 /* maybe turn on internal vREF, and let it settle */ 326 if (ts->use_internal) { 327 req->ref_on = REF_ON; 328 req->xfer[0].tx_buf = &req->ref_on; 329 req->xfer[0].len = 1; 330 spi_message_add_tail(&req->xfer[0], &req->msg); 331 332 req->xfer[1].rx_buf = &req->scratch; 333 req->xfer[1].len = 2; 334 335 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 336 req->xfer[1].delay.value = ts->vref_delay_usecs; 337 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 338 spi_message_add_tail(&req->xfer[1], &req->msg); 339 340 /* Enable reference voltage */ 341 command |= ADS_PD10_REF_ON; 342 } 343 344 /* Enable ADC in every case */ 345 command |= ADS_PD10_ADC_ON; 346 347 /* take sample */ 348 req->command = (u8) command; 349 req->xfer[2].tx_buf = &req->command; 350 req->xfer[2].len = 1; 351 spi_message_add_tail(&req->xfer[2], &req->msg); 352 353 req->xfer[3].rx_buf = &req->sample; 354 req->xfer[3].len = 2; 355 spi_message_add_tail(&req->xfer[3], &req->msg); 356 357 /* REVISIT: take a few more samples, and compare ... */ 358 359 /* converter in low power mode & enable PENIRQ */ 360 req->ref_off = PWRDOWN; 361 req->xfer[4].tx_buf = &req->ref_off; 362 req->xfer[4].len = 1; 363 spi_message_add_tail(&req->xfer[4], &req->msg); 364 365 req->xfer[5].rx_buf = &req->scratch; 366 req->xfer[5].len = 2; 367 CS_CHANGE(req->xfer[5]); 368 spi_message_add_tail(&req->xfer[5], &req->msg); 369 370 mutex_lock(&ts->lock); 371 ads7846_stop(ts); 372 status = spi_sync(spi, &req->msg); 373 ads7846_restart(ts); 374 mutex_unlock(&ts->lock); 375 376 if (status == 0) { 377 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 378 status = be16_to_cpu(req->sample); 379 status = status >> 3; 380 status &= 0x0fff; 381 } 382 383 kfree(req); 384 return status; 385 } 386 387 static int ads7845_read12_ser(struct device *dev, unsigned command) 388 { 389 struct spi_device *spi = to_spi_device(dev); 390 struct ads7846 *ts = dev_get_drvdata(dev); 391 struct ads7845_ser_req *req; 392 int status; 393 394 req = kzalloc(sizeof *req, GFP_KERNEL); 395 if (!req) 396 return -ENOMEM; 397 398 spi_message_init(&req->msg); 399 400 req->command[0] = (u8) command; 401 req->xfer[0].tx_buf = req->command; 402 req->xfer[0].rx_buf = req->sample; 403 req->xfer[0].len = 3; 404 spi_message_add_tail(&req->xfer[0], &req->msg); 405 406 mutex_lock(&ts->lock); 407 ads7846_stop(ts); 408 status = spi_sync(spi, &req->msg); 409 ads7846_restart(ts); 410 mutex_unlock(&ts->lock); 411 412 if (status == 0) { 413 /* BE12 value, then padding */ 414 status = be16_to_cpu(*((u16 *)&req->sample[1])); 415 status = status >> 3; 416 status &= 0x0fff; 417 } 418 419 kfree(req); 420 return status; 421 } 422 423 #if IS_ENABLED(CONFIG_HWMON) 424 425 #define SHOW(name, var, adjust) static ssize_t \ 426 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 427 { \ 428 struct ads7846 *ts = dev_get_drvdata(dev); \ 429 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 430 READ_12BIT_SER(var)); \ 431 if (v < 0) \ 432 return v; \ 433 return sprintf(buf, "%u\n", adjust(ts, v)); \ 434 } \ 435 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 436 437 438 /* Sysfs conventions report temperatures in millidegrees Celsius. 439 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 440 * accuracy scheme without calibration data. For now we won't try either; 441 * userspace sees raw sensor values, and must scale/calibrate appropriately. 442 */ 443 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 444 { 445 return v; 446 } 447 448 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 449 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 450 451 452 /* sysfs conventions report voltages in millivolts. We can convert voltages 453 * if we know vREF. userspace may need to scale vAUX to match the board's 454 * external resistors; we assume that vBATT only uses the internal ones. 455 */ 456 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 457 { 458 unsigned retval = v; 459 460 /* external resistors may scale vAUX into 0..vREF */ 461 retval *= ts->vref_mv; 462 retval = retval >> 12; 463 464 return retval; 465 } 466 467 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 468 { 469 unsigned retval = vaux_adjust(ts, v); 470 471 /* ads7846 has a resistor ladder to scale this signal down */ 472 if (ts->model == 7846) 473 retval *= 4; 474 475 return retval; 476 } 477 478 SHOW(in0_input, vaux, vaux_adjust) 479 SHOW(in1_input, vbatt, vbatt_adjust) 480 481 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 482 int index) 483 { 484 struct device *dev = kobj_to_dev(kobj); 485 struct ads7846 *ts = dev_get_drvdata(dev); 486 487 if (ts->model == 7843 && index < 2) /* in0, in1 */ 488 return 0; 489 if (ts->model == 7845 && index != 2) /* in0 */ 490 return 0; 491 492 return attr->mode; 493 } 494 495 static struct attribute *ads7846_attributes[] = { 496 &dev_attr_temp0.attr, /* 0 */ 497 &dev_attr_temp1.attr, /* 1 */ 498 &dev_attr_in0_input.attr, /* 2 */ 499 &dev_attr_in1_input.attr, /* 3 */ 500 NULL, 501 }; 502 503 static const struct attribute_group ads7846_attr_group = { 504 .attrs = ads7846_attributes, 505 .is_visible = ads7846_is_visible, 506 }; 507 __ATTRIBUTE_GROUPS(ads7846_attr); 508 509 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 510 { 511 /* hwmon sensors need a reference voltage */ 512 switch (ts->model) { 513 case 7846: 514 if (!ts->vref_mv) { 515 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 516 ts->vref_mv = 2500; 517 ts->use_internal = true; 518 } 519 break; 520 case 7845: 521 case 7843: 522 if (!ts->vref_mv) { 523 dev_warn(&spi->dev, 524 "external vREF for ADS%d not specified\n", 525 ts->model); 526 return 0; 527 } 528 break; 529 } 530 531 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 532 ts, ads7846_attr_groups); 533 534 return PTR_ERR_OR_ZERO(ts->hwmon); 535 } 536 537 static void ads784x_hwmon_unregister(struct spi_device *spi, 538 struct ads7846 *ts) 539 { 540 if (ts->hwmon) 541 hwmon_device_unregister(ts->hwmon); 542 } 543 544 #else 545 static inline int ads784x_hwmon_register(struct spi_device *spi, 546 struct ads7846 *ts) 547 { 548 return 0; 549 } 550 551 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 552 struct ads7846 *ts) 553 { 554 } 555 #endif 556 557 static ssize_t ads7846_pen_down_show(struct device *dev, 558 struct device_attribute *attr, char *buf) 559 { 560 struct ads7846 *ts = dev_get_drvdata(dev); 561 562 return sprintf(buf, "%u\n", ts->pendown); 563 } 564 565 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 566 567 static ssize_t ads7846_disable_show(struct device *dev, 568 struct device_attribute *attr, char *buf) 569 { 570 struct ads7846 *ts = dev_get_drvdata(dev); 571 572 return sprintf(buf, "%u\n", ts->disabled); 573 } 574 575 static ssize_t ads7846_disable_store(struct device *dev, 576 struct device_attribute *attr, 577 const char *buf, size_t count) 578 { 579 struct ads7846 *ts = dev_get_drvdata(dev); 580 unsigned int i; 581 int err; 582 583 err = kstrtouint(buf, 10, &i); 584 if (err) 585 return err; 586 587 if (i) 588 ads7846_disable(ts); 589 else 590 ads7846_enable(ts); 591 592 return count; 593 } 594 595 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 596 597 static struct attribute *ads784x_attributes[] = { 598 &dev_attr_pen_down.attr, 599 &dev_attr_disable.attr, 600 NULL, 601 }; 602 603 static const struct attribute_group ads784x_attr_group = { 604 .attrs = ads784x_attributes, 605 }; 606 607 /*--------------------------------------------------------------------------*/ 608 609 static int get_pendown_state(struct ads7846 *ts) 610 { 611 if (ts->get_pendown_state) 612 return ts->get_pendown_state(); 613 614 return !gpio_get_value(ts->gpio_pendown); 615 } 616 617 static void null_wait_for_sync(void) 618 { 619 } 620 621 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 622 { 623 struct ads7846 *ts = ads; 624 625 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 626 /* Start over collecting consistent readings. */ 627 ts->read_rep = 0; 628 /* 629 * Repeat it, if this was the first read or the read 630 * wasn't consistent enough. 631 */ 632 if (ts->read_cnt < ts->debounce_max) { 633 ts->last_read = *val; 634 ts->read_cnt++; 635 return ADS7846_FILTER_REPEAT; 636 } else { 637 /* 638 * Maximum number of debouncing reached and still 639 * not enough number of consistent readings. Abort 640 * the whole sample, repeat it in the next sampling 641 * period. 642 */ 643 ts->read_cnt = 0; 644 return ADS7846_FILTER_IGNORE; 645 } 646 } else { 647 if (++ts->read_rep > ts->debounce_rep) { 648 /* 649 * Got a good reading for this coordinate, 650 * go for the next one. 651 */ 652 ts->read_cnt = 0; 653 ts->read_rep = 0; 654 return ADS7846_FILTER_OK; 655 } else { 656 /* Read more values that are consistent. */ 657 ts->read_cnt++; 658 return ADS7846_FILTER_REPEAT; 659 } 660 } 661 } 662 663 static int ads7846_no_filter(void *ads, int data_idx, int *val) 664 { 665 return ADS7846_FILTER_OK; 666 } 667 668 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 669 { 670 int value; 671 struct spi_transfer *t = 672 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 673 674 if (ts->model == 7845) { 675 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); 676 } else { 677 /* 678 * adjust: on-wire is a must-ignore bit, a BE12 value, then 679 * padding; built from two 8 bit values written msb-first. 680 */ 681 value = be16_to_cpup((__be16 *)t->rx_buf); 682 } 683 684 /* enforce ADC output is 12 bits width */ 685 return (value >> 3) & 0xfff; 686 } 687 688 static void ads7846_update_value(struct spi_message *m, int val) 689 { 690 struct spi_transfer *t = 691 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 692 693 *(u16 *)t->rx_buf = val; 694 } 695 696 static void ads7846_read_state(struct ads7846 *ts) 697 { 698 struct ads7846_packet *packet = ts->packet; 699 struct spi_message *m; 700 int msg_idx = 0; 701 int val; 702 int action; 703 int error; 704 705 while (msg_idx < ts->msg_count) { 706 707 ts->wait_for_sync(); 708 709 m = &ts->msg[msg_idx]; 710 error = spi_sync(ts->spi, m); 711 if (error) { 712 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 713 packet->tc.ignore = true; 714 return; 715 } 716 717 /* 718 * Last message is power down request, no need to convert 719 * or filter the value. 720 */ 721 if (msg_idx < ts->msg_count - 1) { 722 723 val = ads7846_get_value(ts, m); 724 725 action = ts->filter(ts->filter_data, msg_idx, &val); 726 switch (action) { 727 case ADS7846_FILTER_REPEAT: 728 continue; 729 730 case ADS7846_FILTER_IGNORE: 731 packet->tc.ignore = true; 732 msg_idx = ts->msg_count - 1; 733 continue; 734 735 case ADS7846_FILTER_OK: 736 ads7846_update_value(m, val); 737 packet->tc.ignore = false; 738 msg_idx++; 739 break; 740 741 default: 742 BUG(); 743 } 744 } else { 745 msg_idx++; 746 } 747 } 748 } 749 750 static void ads7846_report_state(struct ads7846 *ts) 751 { 752 struct ads7846_packet *packet = ts->packet; 753 unsigned int Rt; 754 u16 x, y, z1, z2; 755 756 /* 757 * ads7846_get_value() does in-place conversion (including byte swap) 758 * from on-the-wire format as part of debouncing to get stable 759 * readings. 760 */ 761 if (ts->model == 7845) { 762 x = *(u16 *)packet->tc.x_buf; 763 y = *(u16 *)packet->tc.y_buf; 764 z1 = 0; 765 z2 = 0; 766 } else { 767 x = packet->tc.x; 768 y = packet->tc.y; 769 z1 = packet->tc.z1; 770 z2 = packet->tc.z2; 771 } 772 773 /* range filtering */ 774 if (x == MAX_12BIT) 775 x = 0; 776 777 if (ts->model == 7843) { 778 Rt = ts->pressure_max / 2; 779 } else if (ts->model == 7845) { 780 if (get_pendown_state(ts)) 781 Rt = ts->pressure_max / 2; 782 else 783 Rt = 0; 784 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 785 } else if (likely(x && z1)) { 786 /* compute touch pressure resistance using equation #2 */ 787 Rt = z2; 788 Rt -= z1; 789 Rt *= x; 790 Rt *= ts->x_plate_ohms; 791 Rt /= z1; 792 Rt = (Rt + 2047) >> 12; 793 } else { 794 Rt = 0; 795 } 796 797 /* 798 * Sample found inconsistent by debouncing or pressure is beyond 799 * the maximum. Don't report it to user space, repeat at least 800 * once more the measurement 801 */ 802 if (packet->tc.ignore || Rt > ts->pressure_max) { 803 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 804 packet->tc.ignore, Rt); 805 return; 806 } 807 808 /* 809 * Maybe check the pendown state before reporting. This discards 810 * false readings when the pen is lifted. 811 */ 812 if (ts->penirq_recheck_delay_usecs) { 813 udelay(ts->penirq_recheck_delay_usecs); 814 if (!get_pendown_state(ts)) 815 Rt = 0; 816 } 817 818 /* 819 * NOTE: We can't rely on the pressure to determine the pen down 820 * state, even this controller has a pressure sensor. The pressure 821 * value can fluctuate for quite a while after lifting the pen and 822 * in some cases may not even settle at the expected value. 823 * 824 * The only safe way to check for the pen up condition is in the 825 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 826 */ 827 if (Rt) { 828 struct input_dev *input = ts->input; 829 830 if (!ts->pendown) { 831 input_report_key(input, BTN_TOUCH, 1); 832 ts->pendown = true; 833 dev_vdbg(&ts->spi->dev, "DOWN\n"); 834 } 835 836 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 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.value = pdata->settle_delay_usecs; 1023 x->delay.unit = SPI_DELAY_UNIT_USECS; 1024 1025 x++; 1026 x->tx_buf = &packet->read_y; 1027 x->len = 1; 1028 spi_message_add_tail(x, m); 1029 1030 x++; 1031 x->rx_buf = &packet->tc.y; 1032 x->len = 2; 1033 spi_message_add_tail(x, m); 1034 } 1035 1036 ts->msg_count++; 1037 m++; 1038 spi_message_init(m); 1039 m->context = ts; 1040 1041 if (ts->model == 7845) { 1042 x++; 1043 packet->read_x_cmd[0] = READ_X(vref); 1044 packet->read_x_cmd[1] = 0; 1045 packet->read_x_cmd[2] = 0; 1046 x->tx_buf = &packet->read_x_cmd[0]; 1047 x->rx_buf = &packet->tc.x_buf[0]; 1048 x->len = 3; 1049 spi_message_add_tail(x, m); 1050 } else { 1051 /* turn y- off, x+ on, then leave in lowpower */ 1052 x++; 1053 packet->read_x = READ_X(vref); 1054 x->tx_buf = &packet->read_x; 1055 x->len = 1; 1056 spi_message_add_tail(x, m); 1057 1058 x++; 1059 x->rx_buf = &packet->tc.x; 1060 x->len = 2; 1061 spi_message_add_tail(x, m); 1062 } 1063 1064 /* ... maybe discard first sample ... */ 1065 if (pdata->settle_delay_usecs) { 1066 x->delay.value = pdata->settle_delay_usecs; 1067 x->delay.unit = SPI_DELAY_UNIT_USECS; 1068 1069 x++; 1070 x->tx_buf = &packet->read_x; 1071 x->len = 1; 1072 spi_message_add_tail(x, m); 1073 1074 x++; 1075 x->rx_buf = &packet->tc.x; 1076 x->len = 2; 1077 spi_message_add_tail(x, m); 1078 } 1079 1080 /* turn y+ off, x- on; we'll use formula #2 */ 1081 if (ts->model == 7846) { 1082 ts->msg_count++; 1083 m++; 1084 spi_message_init(m); 1085 m->context = ts; 1086 1087 x++; 1088 packet->read_z1 = READ_Z1(vref); 1089 x->tx_buf = &packet->read_z1; 1090 x->len = 1; 1091 spi_message_add_tail(x, m); 1092 1093 x++; 1094 x->rx_buf = &packet->tc.z1; 1095 x->len = 2; 1096 spi_message_add_tail(x, m); 1097 1098 /* ... maybe discard first sample ... */ 1099 if (pdata->settle_delay_usecs) { 1100 x->delay.value = pdata->settle_delay_usecs; 1101 x->delay.unit = SPI_DELAY_UNIT_USECS; 1102 1103 x++; 1104 x->tx_buf = &packet->read_z1; 1105 x->len = 1; 1106 spi_message_add_tail(x, m); 1107 1108 x++; 1109 x->rx_buf = &packet->tc.z1; 1110 x->len = 2; 1111 spi_message_add_tail(x, m); 1112 } 1113 1114 ts->msg_count++; 1115 m++; 1116 spi_message_init(m); 1117 m->context = ts; 1118 1119 x++; 1120 packet->read_z2 = READ_Z2(vref); 1121 x->tx_buf = &packet->read_z2; 1122 x->len = 1; 1123 spi_message_add_tail(x, m); 1124 1125 x++; 1126 x->rx_buf = &packet->tc.z2; 1127 x->len = 2; 1128 spi_message_add_tail(x, m); 1129 1130 /* ... maybe discard first sample ... */ 1131 if (pdata->settle_delay_usecs) { 1132 x->delay.value = pdata->settle_delay_usecs; 1133 x->delay.unit = SPI_DELAY_UNIT_USECS; 1134 1135 x++; 1136 x->tx_buf = &packet->read_z2; 1137 x->len = 1; 1138 spi_message_add_tail(x, m); 1139 1140 x++; 1141 x->rx_buf = &packet->tc.z2; 1142 x->len = 2; 1143 spi_message_add_tail(x, m); 1144 } 1145 } 1146 1147 /* power down */ 1148 ts->msg_count++; 1149 m++; 1150 spi_message_init(m); 1151 m->context = ts; 1152 1153 if (ts->model == 7845) { 1154 x++; 1155 packet->pwrdown_cmd[0] = PWRDOWN; 1156 packet->pwrdown_cmd[1] = 0; 1157 packet->pwrdown_cmd[2] = 0; 1158 x->tx_buf = &packet->pwrdown_cmd[0]; 1159 x->len = 3; 1160 } else { 1161 x++; 1162 packet->pwrdown = PWRDOWN; 1163 x->tx_buf = &packet->pwrdown; 1164 x->len = 1; 1165 spi_message_add_tail(x, m); 1166 1167 x++; 1168 x->rx_buf = &packet->dummy; 1169 x->len = 2; 1170 } 1171 1172 CS_CHANGE(*x); 1173 spi_message_add_tail(x, m); 1174 } 1175 1176 #ifdef CONFIG_OF 1177 static const struct of_device_id ads7846_dt_ids[] = { 1178 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1179 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1180 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1181 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1182 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1183 { } 1184 }; 1185 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1186 1187 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1188 { 1189 struct ads7846_platform_data *pdata; 1190 struct device_node *node = dev->of_node; 1191 const struct of_device_id *match; 1192 u32 value; 1193 1194 if (!node) { 1195 dev_err(dev, "Device does not have associated DT data\n"); 1196 return ERR_PTR(-EINVAL); 1197 } 1198 1199 match = of_match_device(ads7846_dt_ids, dev); 1200 if (!match) { 1201 dev_err(dev, "Unknown device model\n"); 1202 return ERR_PTR(-EINVAL); 1203 } 1204 1205 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1206 if (!pdata) 1207 return ERR_PTR(-ENOMEM); 1208 1209 pdata->model = (unsigned long)match->data; 1210 1211 of_property_read_u16(node, "ti,vref-delay-usecs", 1212 &pdata->vref_delay_usecs); 1213 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1214 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1215 1216 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1217 1218 of_property_read_u16(node, "ti,settle-delay-usec", 1219 &pdata->settle_delay_usecs); 1220 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1221 &pdata->penirq_recheck_delay_usecs); 1222 1223 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1224 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1225 1226 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1227 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1228 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1229 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1230 1231 /* 1232 * touchscreen-max-pressure gets parsed during 1233 * touchscreen_parse_properties() 1234 */ 1235 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1236 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1237 pdata->pressure_min = (u16) value; 1238 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1239 1240 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1241 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1242 pdata->debounce_max = (u16) value; 1243 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1244 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1245 1246 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1247 &pdata->gpio_pendown_debounce); 1248 1249 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1250 of_property_read_bool(node, "linux,wakeup"); 1251 1252 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1253 1254 return pdata; 1255 } 1256 #else 1257 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1258 { 1259 dev_err(dev, "no platform data defined\n"); 1260 return ERR_PTR(-EINVAL); 1261 } 1262 #endif 1263 1264 static int ads7846_probe(struct spi_device *spi) 1265 { 1266 const struct ads7846_platform_data *pdata; 1267 struct ads7846 *ts; 1268 struct ads7846_packet *packet; 1269 struct input_dev *input_dev; 1270 unsigned long irq_flags; 1271 int err; 1272 1273 if (!spi->irq) { 1274 dev_dbg(&spi->dev, "no IRQ?\n"); 1275 return -EINVAL; 1276 } 1277 1278 /* don't exceed max specified sample rate */ 1279 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1280 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1281 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1282 return -EINVAL; 1283 } 1284 1285 /* 1286 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1287 * that even if the hardware can do that, the SPI controller driver 1288 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1289 */ 1290 spi->bits_per_word = 8; 1291 spi->mode = SPI_MODE_0; 1292 err = spi_setup(spi); 1293 if (err < 0) 1294 return err; 1295 1296 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1297 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1298 input_dev = input_allocate_device(); 1299 if (!ts || !packet || !input_dev) { 1300 err = -ENOMEM; 1301 goto err_free_mem; 1302 } 1303 1304 spi_set_drvdata(spi, ts); 1305 1306 ts->packet = packet; 1307 ts->spi = spi; 1308 ts->input = input_dev; 1309 1310 mutex_init(&ts->lock); 1311 init_waitqueue_head(&ts->wait); 1312 1313 pdata = dev_get_platdata(&spi->dev); 1314 if (!pdata) { 1315 pdata = ads7846_probe_dt(&spi->dev); 1316 if (IS_ERR(pdata)) { 1317 err = PTR_ERR(pdata); 1318 goto err_free_mem; 1319 } 1320 } 1321 1322 ts->model = pdata->model ? : 7846; 1323 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1324 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1325 ts->vref_mv = pdata->vref_mv; 1326 1327 if (pdata->filter != NULL) { 1328 if (pdata->filter_init != NULL) { 1329 err = pdata->filter_init(pdata, &ts->filter_data); 1330 if (err < 0) 1331 goto err_free_mem; 1332 } 1333 ts->filter = pdata->filter; 1334 ts->filter_cleanup = pdata->filter_cleanup; 1335 } else if (pdata->debounce_max) { 1336 ts->debounce_max = pdata->debounce_max; 1337 if (ts->debounce_max < 2) 1338 ts->debounce_max = 2; 1339 ts->debounce_tol = pdata->debounce_tol; 1340 ts->debounce_rep = pdata->debounce_rep; 1341 ts->filter = ads7846_debounce_filter; 1342 ts->filter_data = ts; 1343 } else { 1344 ts->filter = ads7846_no_filter; 1345 } 1346 1347 err = ads7846_setup_pendown(spi, ts, pdata); 1348 if (err) 1349 goto err_cleanup_filter; 1350 1351 if (pdata->penirq_recheck_delay_usecs) 1352 ts->penirq_recheck_delay_usecs = 1353 pdata->penirq_recheck_delay_usecs; 1354 1355 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1356 1357 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1358 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1359 1360 input_dev->name = ts->name; 1361 input_dev->phys = ts->phys; 1362 input_dev->dev.parent = &spi->dev; 1363 1364 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1365 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1366 input_set_abs_params(input_dev, ABS_X, 1367 pdata->x_min ? : 0, 1368 pdata->x_max ? : MAX_12BIT, 1369 0, 0); 1370 input_set_abs_params(input_dev, ABS_Y, 1371 pdata->y_min ? : 0, 1372 pdata->y_max ? : MAX_12BIT, 1373 0, 0); 1374 input_set_abs_params(input_dev, ABS_PRESSURE, 1375 pdata->pressure_min, pdata->pressure_max, 0, 0); 1376 1377 /* 1378 * Parse common framework properties. Must be done here to ensure the 1379 * correct behaviour in case of using the legacy vendor bindings. The 1380 * general binding value overrides the vendor specific one. 1381 */ 1382 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1383 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1384 1385 /* 1386 * Check if legacy ti,swap-xy binding is used instead of 1387 * touchscreen-swapped-x-y 1388 */ 1389 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1390 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1391 ts->core_prop.swap_x_y = true; 1392 } 1393 1394 ads7846_setup_spi_msg(ts, pdata); 1395 1396 ts->reg = regulator_get(&spi->dev, "vcc"); 1397 if (IS_ERR(ts->reg)) { 1398 err = PTR_ERR(ts->reg); 1399 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1400 goto err_free_gpio; 1401 } 1402 1403 err = regulator_enable(ts->reg); 1404 if (err) { 1405 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1406 goto err_put_regulator; 1407 } 1408 1409 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1410 irq_flags |= IRQF_ONESHOT; 1411 1412 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1413 irq_flags, spi->dev.driver->name, ts); 1414 if (err && !pdata->irq_flags) { 1415 dev_info(&spi->dev, 1416 "trying pin change workaround on irq %d\n", spi->irq); 1417 irq_flags |= IRQF_TRIGGER_RISING; 1418 err = request_threaded_irq(spi->irq, 1419 ads7846_hard_irq, ads7846_irq, 1420 irq_flags, spi->dev.driver->name, ts); 1421 } 1422 1423 if (err) { 1424 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1425 goto err_disable_regulator; 1426 } 1427 1428 err = ads784x_hwmon_register(spi, ts); 1429 if (err) 1430 goto err_free_irq; 1431 1432 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1433 1434 /* 1435 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1436 * the touchscreen, in case it's not connected. 1437 */ 1438 if (ts->model == 7845) 1439 ads7845_read12_ser(&spi->dev, PWRDOWN); 1440 else 1441 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1442 1443 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1444 if (err) 1445 goto err_remove_hwmon; 1446 1447 err = input_register_device(input_dev); 1448 if (err) 1449 goto err_remove_attr_group; 1450 1451 device_init_wakeup(&spi->dev, pdata->wakeup); 1452 1453 /* 1454 * If device does not carry platform data we must have allocated it 1455 * when parsing DT data. 1456 */ 1457 if (!dev_get_platdata(&spi->dev)) 1458 devm_kfree(&spi->dev, (void *)pdata); 1459 1460 return 0; 1461 1462 err_remove_attr_group: 1463 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1464 err_remove_hwmon: 1465 ads784x_hwmon_unregister(spi, ts); 1466 err_free_irq: 1467 free_irq(spi->irq, ts); 1468 err_disable_regulator: 1469 regulator_disable(ts->reg); 1470 err_put_regulator: 1471 regulator_put(ts->reg); 1472 err_free_gpio: 1473 if (!ts->get_pendown_state) 1474 gpio_free(ts->gpio_pendown); 1475 err_cleanup_filter: 1476 if (ts->filter_cleanup) 1477 ts->filter_cleanup(ts->filter_data); 1478 err_free_mem: 1479 input_free_device(input_dev); 1480 kfree(packet); 1481 kfree(ts); 1482 return err; 1483 } 1484 1485 static int ads7846_remove(struct spi_device *spi) 1486 { 1487 struct ads7846 *ts = spi_get_drvdata(spi); 1488 1489 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1490 1491 ads7846_disable(ts); 1492 free_irq(ts->spi->irq, ts); 1493 1494 input_unregister_device(ts->input); 1495 1496 ads784x_hwmon_unregister(spi, ts); 1497 1498 regulator_put(ts->reg); 1499 1500 if (!ts->get_pendown_state) { 1501 /* 1502 * If we are not using specialized pendown method we must 1503 * have been relying on gpio we set up ourselves. 1504 */ 1505 gpio_free(ts->gpio_pendown); 1506 } 1507 1508 if (ts->filter_cleanup) 1509 ts->filter_cleanup(ts->filter_data); 1510 1511 kfree(ts->packet); 1512 kfree(ts); 1513 1514 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1515 1516 return 0; 1517 } 1518 1519 static struct spi_driver ads7846_driver = { 1520 .driver = { 1521 .name = "ads7846", 1522 .pm = &ads7846_pm, 1523 .of_match_table = of_match_ptr(ads7846_dt_ids), 1524 }, 1525 .probe = ads7846_probe, 1526 .remove = ads7846_remove, 1527 }; 1528 1529 module_spi_driver(ads7846_driver); 1530 1531 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1532 MODULE_LICENSE("GPL"); 1533 MODULE_ALIAS("spi:ads7846"); 1534