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 static int get_pendown_state(struct ads7846 *ts) 203 { 204 if (ts->get_pendown_state) 205 return ts->get_pendown_state(); 206 207 return !gpio_get_value(ts->gpio_pendown); 208 } 209 210 static void ads7846_report_pen_up(struct ads7846 *ts) 211 { 212 struct input_dev *input = ts->input; 213 214 input_report_key(input, BTN_TOUCH, 0); 215 input_report_abs(input, ABS_PRESSURE, 0); 216 input_sync(input); 217 218 ts->pendown = false; 219 dev_vdbg(&ts->spi->dev, "UP\n"); 220 } 221 222 /* Must be called with ts->lock held */ 223 static void ads7846_stop(struct ads7846 *ts) 224 { 225 if (!ts->disabled && !ts->suspended) { 226 /* Signal IRQ thread to stop polling and disable the handler. */ 227 ts->stopped = true; 228 mb(); 229 wake_up(&ts->wait); 230 disable_irq(ts->spi->irq); 231 } 232 } 233 234 /* Must be called with ts->lock held */ 235 static void ads7846_restart(struct ads7846 *ts) 236 { 237 if (!ts->disabled && !ts->suspended) { 238 /* Check if pen was released since last stop */ 239 if (ts->pendown && !get_pendown_state(ts)) 240 ads7846_report_pen_up(ts); 241 242 /* Tell IRQ thread that it may poll the device. */ 243 ts->stopped = false; 244 mb(); 245 enable_irq(ts->spi->irq); 246 } 247 } 248 249 /* Must be called with ts->lock held */ 250 static void __ads7846_disable(struct ads7846 *ts) 251 { 252 ads7846_stop(ts); 253 regulator_disable(ts->reg); 254 255 /* 256 * We know the chip's in low power mode since we always 257 * leave it that way after every request 258 */ 259 } 260 261 /* Must be called with ts->lock held */ 262 static void __ads7846_enable(struct ads7846 *ts) 263 { 264 int error; 265 266 error = regulator_enable(ts->reg); 267 if (error != 0) 268 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 269 270 ads7846_restart(ts); 271 } 272 273 static void ads7846_disable(struct ads7846 *ts) 274 { 275 mutex_lock(&ts->lock); 276 277 if (!ts->disabled) { 278 279 if (!ts->suspended) 280 __ads7846_disable(ts); 281 282 ts->disabled = true; 283 } 284 285 mutex_unlock(&ts->lock); 286 } 287 288 static void ads7846_enable(struct ads7846 *ts) 289 { 290 mutex_lock(&ts->lock); 291 292 if (ts->disabled) { 293 294 ts->disabled = false; 295 296 if (!ts->suspended) 297 __ads7846_enable(ts); 298 } 299 300 mutex_unlock(&ts->lock); 301 } 302 303 /*--------------------------------------------------------------------------*/ 304 305 /* 306 * Non-touchscreen sensors only use single-ended conversions. 307 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 308 * ads7846 lets that pin be unconnected, to use internal vREF. 309 */ 310 311 struct ser_req { 312 u8 ref_on; 313 u8 command; 314 u8 ref_off; 315 u16 scratch; 316 struct spi_message msg; 317 struct spi_transfer xfer[6]; 318 /* 319 * DMA (thus cache coherency maintenance) requires the 320 * transfer buffers to live in their own cache lines. 321 */ 322 __be16 sample ____cacheline_aligned; 323 }; 324 325 struct ads7845_ser_req { 326 u8 command[3]; 327 struct spi_message msg; 328 struct spi_transfer xfer[2]; 329 /* 330 * DMA (thus cache coherency maintenance) requires the 331 * transfer buffers to live in their own cache lines. 332 */ 333 u8 sample[3] ____cacheline_aligned; 334 }; 335 336 static int ads7846_read12_ser(struct device *dev, unsigned command) 337 { 338 struct spi_device *spi = to_spi_device(dev); 339 struct ads7846 *ts = dev_get_drvdata(dev); 340 struct ser_req *req; 341 int status; 342 343 req = kzalloc(sizeof *req, GFP_KERNEL); 344 if (!req) 345 return -ENOMEM; 346 347 spi_message_init(&req->msg); 348 349 /* maybe turn on internal vREF, and let it settle */ 350 if (ts->use_internal) { 351 req->ref_on = REF_ON; 352 req->xfer[0].tx_buf = &req->ref_on; 353 req->xfer[0].len = 1; 354 spi_message_add_tail(&req->xfer[0], &req->msg); 355 356 req->xfer[1].rx_buf = &req->scratch; 357 req->xfer[1].len = 2; 358 359 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 360 req->xfer[1].delay.value = ts->vref_delay_usecs; 361 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 362 spi_message_add_tail(&req->xfer[1], &req->msg); 363 364 /* Enable reference voltage */ 365 command |= ADS_PD10_REF_ON; 366 } 367 368 /* Enable ADC in every case */ 369 command |= ADS_PD10_ADC_ON; 370 371 /* take sample */ 372 req->command = (u8) command; 373 req->xfer[2].tx_buf = &req->command; 374 req->xfer[2].len = 1; 375 spi_message_add_tail(&req->xfer[2], &req->msg); 376 377 req->xfer[3].rx_buf = &req->sample; 378 req->xfer[3].len = 2; 379 spi_message_add_tail(&req->xfer[3], &req->msg); 380 381 /* REVISIT: take a few more samples, and compare ... */ 382 383 /* converter in low power mode & enable PENIRQ */ 384 req->ref_off = PWRDOWN; 385 req->xfer[4].tx_buf = &req->ref_off; 386 req->xfer[4].len = 1; 387 spi_message_add_tail(&req->xfer[4], &req->msg); 388 389 req->xfer[5].rx_buf = &req->scratch; 390 req->xfer[5].len = 2; 391 CS_CHANGE(req->xfer[5]); 392 spi_message_add_tail(&req->xfer[5], &req->msg); 393 394 mutex_lock(&ts->lock); 395 ads7846_stop(ts); 396 status = spi_sync(spi, &req->msg); 397 ads7846_restart(ts); 398 mutex_unlock(&ts->lock); 399 400 if (status == 0) { 401 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 402 status = be16_to_cpu(req->sample); 403 status = status >> 3; 404 status &= 0x0fff; 405 } 406 407 kfree(req); 408 return status; 409 } 410 411 static int ads7845_read12_ser(struct device *dev, unsigned command) 412 { 413 struct spi_device *spi = to_spi_device(dev); 414 struct ads7846 *ts = dev_get_drvdata(dev); 415 struct ads7845_ser_req *req; 416 int status; 417 418 req = kzalloc(sizeof *req, GFP_KERNEL); 419 if (!req) 420 return -ENOMEM; 421 422 spi_message_init(&req->msg); 423 424 req->command[0] = (u8) command; 425 req->xfer[0].tx_buf = req->command; 426 req->xfer[0].rx_buf = req->sample; 427 req->xfer[0].len = 3; 428 spi_message_add_tail(&req->xfer[0], &req->msg); 429 430 mutex_lock(&ts->lock); 431 ads7846_stop(ts); 432 status = spi_sync(spi, &req->msg); 433 ads7846_restart(ts); 434 mutex_unlock(&ts->lock); 435 436 if (status == 0) { 437 /* BE12 value, then padding */ 438 status = be16_to_cpu(*((u16 *)&req->sample[1])); 439 status = status >> 3; 440 status &= 0x0fff; 441 } 442 443 kfree(req); 444 return status; 445 } 446 447 #if IS_ENABLED(CONFIG_HWMON) 448 449 #define SHOW(name, var, adjust) static ssize_t \ 450 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 451 { \ 452 struct ads7846 *ts = dev_get_drvdata(dev); \ 453 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 454 READ_12BIT_SER(var)); \ 455 if (v < 0) \ 456 return v; \ 457 return sprintf(buf, "%u\n", adjust(ts, v)); \ 458 } \ 459 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 460 461 462 /* Sysfs conventions report temperatures in millidegrees Celsius. 463 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 464 * accuracy scheme without calibration data. For now we won't try either; 465 * userspace sees raw sensor values, and must scale/calibrate appropriately. 466 */ 467 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 468 { 469 return v; 470 } 471 472 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 473 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 474 475 476 /* sysfs conventions report voltages in millivolts. We can convert voltages 477 * if we know vREF. userspace may need to scale vAUX to match the board's 478 * external resistors; we assume that vBATT only uses the internal ones. 479 */ 480 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 481 { 482 unsigned retval = v; 483 484 /* external resistors may scale vAUX into 0..vREF */ 485 retval *= ts->vref_mv; 486 retval = retval >> 12; 487 488 return retval; 489 } 490 491 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 492 { 493 unsigned retval = vaux_adjust(ts, v); 494 495 /* ads7846 has a resistor ladder to scale this signal down */ 496 if (ts->model == 7846) 497 retval *= 4; 498 499 return retval; 500 } 501 502 SHOW(in0_input, vaux, vaux_adjust) 503 SHOW(in1_input, vbatt, vbatt_adjust) 504 505 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 506 int index) 507 { 508 struct device *dev = container_of(kobj, struct device, kobj); 509 struct ads7846 *ts = dev_get_drvdata(dev); 510 511 if (ts->model == 7843 && index < 2) /* in0, in1 */ 512 return 0; 513 if (ts->model == 7845 && index != 2) /* in0 */ 514 return 0; 515 516 return attr->mode; 517 } 518 519 static struct attribute *ads7846_attributes[] = { 520 &dev_attr_temp0.attr, /* 0 */ 521 &dev_attr_temp1.attr, /* 1 */ 522 &dev_attr_in0_input.attr, /* 2 */ 523 &dev_attr_in1_input.attr, /* 3 */ 524 NULL, 525 }; 526 527 static const struct attribute_group ads7846_attr_group = { 528 .attrs = ads7846_attributes, 529 .is_visible = ads7846_is_visible, 530 }; 531 __ATTRIBUTE_GROUPS(ads7846_attr); 532 533 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 534 { 535 /* hwmon sensors need a reference voltage */ 536 switch (ts->model) { 537 case 7846: 538 if (!ts->vref_mv) { 539 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 540 ts->vref_mv = 2500; 541 ts->use_internal = true; 542 } 543 break; 544 case 7845: 545 case 7843: 546 if (!ts->vref_mv) { 547 dev_warn(&spi->dev, 548 "external vREF for ADS%d not specified\n", 549 ts->model); 550 return 0; 551 } 552 break; 553 } 554 555 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 556 ts, ads7846_attr_groups); 557 558 return PTR_ERR_OR_ZERO(ts->hwmon); 559 } 560 561 static void ads784x_hwmon_unregister(struct spi_device *spi, 562 struct ads7846 *ts) 563 { 564 if (ts->hwmon) 565 hwmon_device_unregister(ts->hwmon); 566 } 567 568 #else 569 static inline int ads784x_hwmon_register(struct spi_device *spi, 570 struct ads7846 *ts) 571 { 572 return 0; 573 } 574 575 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 576 struct ads7846 *ts) 577 { 578 } 579 #endif 580 581 static ssize_t ads7846_pen_down_show(struct device *dev, 582 struct device_attribute *attr, char *buf) 583 { 584 struct ads7846 *ts = dev_get_drvdata(dev); 585 586 return sprintf(buf, "%u\n", ts->pendown); 587 } 588 589 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 590 591 static ssize_t ads7846_disable_show(struct device *dev, 592 struct device_attribute *attr, char *buf) 593 { 594 struct ads7846 *ts = dev_get_drvdata(dev); 595 596 return sprintf(buf, "%u\n", ts->disabled); 597 } 598 599 static ssize_t ads7846_disable_store(struct device *dev, 600 struct device_attribute *attr, 601 const char *buf, size_t count) 602 { 603 struct ads7846 *ts = dev_get_drvdata(dev); 604 unsigned int i; 605 int err; 606 607 err = kstrtouint(buf, 10, &i); 608 if (err) 609 return err; 610 611 if (i) 612 ads7846_disable(ts); 613 else 614 ads7846_enable(ts); 615 616 return count; 617 } 618 619 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 620 621 static struct attribute *ads784x_attributes[] = { 622 &dev_attr_pen_down.attr, 623 &dev_attr_disable.attr, 624 NULL, 625 }; 626 627 static const struct attribute_group ads784x_attr_group = { 628 .attrs = ads784x_attributes, 629 }; 630 631 /*--------------------------------------------------------------------------*/ 632 633 static void null_wait_for_sync(void) 634 { 635 } 636 637 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 638 { 639 struct ads7846 *ts = ads; 640 641 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 642 /* Start over collecting consistent readings. */ 643 ts->read_rep = 0; 644 /* 645 * Repeat it, if this was the first read or the read 646 * wasn't consistent enough. 647 */ 648 if (ts->read_cnt < ts->debounce_max) { 649 ts->last_read = *val; 650 ts->read_cnt++; 651 return ADS7846_FILTER_REPEAT; 652 } else { 653 /* 654 * Maximum number of debouncing reached and still 655 * not enough number of consistent readings. Abort 656 * the whole sample, repeat it in the next sampling 657 * period. 658 */ 659 ts->read_cnt = 0; 660 return ADS7846_FILTER_IGNORE; 661 } 662 } else { 663 if (++ts->read_rep > ts->debounce_rep) { 664 /* 665 * Got a good reading for this coordinate, 666 * go for the next one. 667 */ 668 ts->read_cnt = 0; 669 ts->read_rep = 0; 670 return ADS7846_FILTER_OK; 671 } else { 672 /* Read more values that are consistent. */ 673 ts->read_cnt++; 674 return ADS7846_FILTER_REPEAT; 675 } 676 } 677 } 678 679 static int ads7846_no_filter(void *ads, int data_idx, int *val) 680 { 681 return ADS7846_FILTER_OK; 682 } 683 684 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 685 { 686 int value; 687 struct spi_transfer *t = 688 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 689 690 if (ts->model == 7845) { 691 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); 692 } else { 693 /* 694 * adjust: on-wire is a must-ignore bit, a BE12 value, then 695 * padding; built from two 8 bit values written msb-first. 696 */ 697 value = be16_to_cpup((__be16 *)t->rx_buf); 698 } 699 700 /* enforce ADC output is 12 bits width */ 701 return (value >> 3) & 0xfff; 702 } 703 704 static void ads7846_update_value(struct spi_message *m, int val) 705 { 706 struct spi_transfer *t = 707 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 708 709 *(u16 *)t->rx_buf = val; 710 } 711 712 static void ads7846_read_state(struct ads7846 *ts) 713 { 714 struct ads7846_packet *packet = ts->packet; 715 struct spi_message *m; 716 int msg_idx = 0; 717 int val; 718 int action; 719 int error; 720 721 while (msg_idx < ts->msg_count) { 722 723 ts->wait_for_sync(); 724 725 m = &ts->msg[msg_idx]; 726 error = spi_sync(ts->spi, m); 727 if (error) { 728 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 729 packet->tc.ignore = true; 730 return; 731 } 732 733 /* 734 * Last message is power down request, no need to convert 735 * or filter the value. 736 */ 737 if (msg_idx < ts->msg_count - 1) { 738 739 val = ads7846_get_value(ts, m); 740 741 action = ts->filter(ts->filter_data, msg_idx, &val); 742 switch (action) { 743 case ADS7846_FILTER_REPEAT: 744 continue; 745 746 case ADS7846_FILTER_IGNORE: 747 packet->tc.ignore = true; 748 msg_idx = ts->msg_count - 1; 749 continue; 750 751 case ADS7846_FILTER_OK: 752 ads7846_update_value(m, val); 753 packet->tc.ignore = false; 754 msg_idx++; 755 break; 756 757 default: 758 BUG(); 759 } 760 } else { 761 msg_idx++; 762 } 763 } 764 } 765 766 static void ads7846_report_state(struct ads7846 *ts) 767 { 768 struct ads7846_packet *packet = ts->packet; 769 unsigned int Rt; 770 u16 x, y, z1, z2; 771 772 /* 773 * ads7846_get_value() does in-place conversion (including byte swap) 774 * from on-the-wire format as part of debouncing to get stable 775 * readings. 776 */ 777 if (ts->model == 7845) { 778 x = *(u16 *)packet->tc.x_buf; 779 y = *(u16 *)packet->tc.y_buf; 780 z1 = 0; 781 z2 = 0; 782 } else { 783 x = packet->tc.x; 784 y = packet->tc.y; 785 z1 = packet->tc.z1; 786 z2 = packet->tc.z2; 787 } 788 789 /* range filtering */ 790 if (x == MAX_12BIT) 791 x = 0; 792 793 if (ts->model == 7843) { 794 Rt = ts->pressure_max / 2; 795 } else if (ts->model == 7845) { 796 if (get_pendown_state(ts)) 797 Rt = ts->pressure_max / 2; 798 else 799 Rt = 0; 800 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 801 } else if (likely(x && z1)) { 802 /* compute touch pressure resistance using equation #2 */ 803 Rt = z2; 804 Rt -= z1; 805 Rt *= ts->x_plate_ohms; 806 Rt = DIV_ROUND_CLOSEST(Rt, 16); 807 Rt *= x; 808 Rt /= z1; 809 Rt = DIV_ROUND_CLOSEST(Rt, 256); 810 } else { 811 Rt = 0; 812 } 813 814 /* 815 * Sample found inconsistent by debouncing or pressure is beyond 816 * the maximum. Don't report it to user space, repeat at least 817 * once more the measurement 818 */ 819 if (packet->tc.ignore || Rt > ts->pressure_max) { 820 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 821 packet->tc.ignore, Rt); 822 return; 823 } 824 825 /* 826 * Maybe check the pendown state before reporting. This discards 827 * false readings when the pen is lifted. 828 */ 829 if (ts->penirq_recheck_delay_usecs) { 830 udelay(ts->penirq_recheck_delay_usecs); 831 if (!get_pendown_state(ts)) 832 Rt = 0; 833 } 834 835 /* 836 * NOTE: We can't rely on the pressure to determine the pen down 837 * state, even this controller has a pressure sensor. The pressure 838 * value can fluctuate for quite a while after lifting the pen and 839 * in some cases may not even settle at the expected value. 840 * 841 * The only safe way to check for the pen up condition is in the 842 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 843 */ 844 if (Rt) { 845 struct input_dev *input = ts->input; 846 847 if (!ts->pendown) { 848 input_report_key(input, BTN_TOUCH, 1); 849 ts->pendown = true; 850 dev_vdbg(&ts->spi->dev, "DOWN\n"); 851 } 852 853 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 854 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 855 856 input_sync(input); 857 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 858 } 859 } 860 861 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 862 { 863 struct ads7846 *ts = handle; 864 865 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 866 } 867 868 869 static irqreturn_t ads7846_irq(int irq, void *handle) 870 { 871 struct ads7846 *ts = handle; 872 873 /* Start with a small delay before checking pendown state */ 874 msleep(TS_POLL_DELAY); 875 876 while (!ts->stopped && get_pendown_state(ts)) { 877 878 /* pen is down, continue with the measurement */ 879 ads7846_read_state(ts); 880 881 if (!ts->stopped) 882 ads7846_report_state(ts); 883 884 wait_event_timeout(ts->wait, ts->stopped, 885 msecs_to_jiffies(TS_POLL_PERIOD)); 886 } 887 888 if (ts->pendown && !ts->stopped) 889 ads7846_report_pen_up(ts); 890 891 return IRQ_HANDLED; 892 } 893 894 static int __maybe_unused ads7846_suspend(struct device *dev) 895 { 896 struct ads7846 *ts = dev_get_drvdata(dev); 897 898 mutex_lock(&ts->lock); 899 900 if (!ts->suspended) { 901 902 if (!ts->disabled) 903 __ads7846_disable(ts); 904 905 if (device_may_wakeup(&ts->spi->dev)) 906 enable_irq_wake(ts->spi->irq); 907 908 ts->suspended = true; 909 } 910 911 mutex_unlock(&ts->lock); 912 913 return 0; 914 } 915 916 static int __maybe_unused ads7846_resume(struct device *dev) 917 { 918 struct ads7846 *ts = dev_get_drvdata(dev); 919 920 mutex_lock(&ts->lock); 921 922 if (ts->suspended) { 923 924 ts->suspended = false; 925 926 if (device_may_wakeup(&ts->spi->dev)) 927 disable_irq_wake(ts->spi->irq); 928 929 if (!ts->disabled) 930 __ads7846_enable(ts); 931 } 932 933 mutex_unlock(&ts->lock); 934 935 return 0; 936 } 937 938 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 939 940 static int ads7846_setup_pendown(struct spi_device *spi, 941 struct ads7846 *ts, 942 const struct ads7846_platform_data *pdata) 943 { 944 int err; 945 946 /* 947 * REVISIT when the irq can be triggered active-low, or if for some 948 * reason the touchscreen isn't hooked up, we don't need to access 949 * the pendown state. 950 */ 951 952 if (pdata->get_pendown_state) { 953 ts->get_pendown_state = pdata->get_pendown_state; 954 } else if (gpio_is_valid(pdata->gpio_pendown)) { 955 956 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 957 "ads7846_pendown"); 958 if (err) { 959 dev_err(&spi->dev, 960 "failed to request/setup pendown GPIO%d: %d\n", 961 pdata->gpio_pendown, err); 962 return err; 963 } 964 965 ts->gpio_pendown = pdata->gpio_pendown; 966 967 if (pdata->gpio_pendown_debounce) 968 gpio_set_debounce(pdata->gpio_pendown, 969 pdata->gpio_pendown_debounce); 970 } else { 971 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 972 return -EINVAL; 973 } 974 975 return 0; 976 } 977 978 /* 979 * Set up the transfers to read touchscreen state; this assumes we 980 * use formula #2 for pressure, not #3. 981 */ 982 static void ads7846_setup_spi_msg(struct ads7846 *ts, 983 const struct ads7846_platform_data *pdata) 984 { 985 struct spi_message *m = &ts->msg[0]; 986 struct spi_transfer *x = ts->xfer; 987 struct ads7846_packet *packet = ts->packet; 988 int vref = pdata->keep_vref_on; 989 990 if (ts->model == 7873) { 991 /* 992 * The AD7873 is almost identical to the ADS7846 993 * keep VREF off during differential/ratiometric 994 * conversion modes. 995 */ 996 ts->model = 7846; 997 vref = 0; 998 } 999 1000 ts->msg_count = 1; 1001 spi_message_init(m); 1002 m->context = ts; 1003 1004 if (ts->model == 7845) { 1005 packet->read_y_cmd[0] = READ_Y(vref); 1006 packet->read_y_cmd[1] = 0; 1007 packet->read_y_cmd[2] = 0; 1008 x->tx_buf = &packet->read_y_cmd[0]; 1009 x->rx_buf = &packet->tc.y_buf[0]; 1010 x->len = 3; 1011 spi_message_add_tail(x, m); 1012 } else { 1013 /* y- still on; turn on only y+ (and ADC) */ 1014 packet->read_y = READ_Y(vref); 1015 x->tx_buf = &packet->read_y; 1016 x->len = 1; 1017 spi_message_add_tail(x, m); 1018 1019 x++; 1020 x->rx_buf = &packet->tc.y; 1021 x->len = 2; 1022 spi_message_add_tail(x, m); 1023 } 1024 1025 /* 1026 * The first sample after switching drivers can be low quality; 1027 * optionally discard it, using a second one after the signals 1028 * have had enough time to stabilize. 1029 */ 1030 if (pdata->settle_delay_usecs) { 1031 x->delay.value = pdata->settle_delay_usecs; 1032 x->delay.unit = SPI_DELAY_UNIT_USECS; 1033 1034 x++; 1035 x->tx_buf = &packet->read_y; 1036 x->len = 1; 1037 spi_message_add_tail(x, m); 1038 1039 x++; 1040 x->rx_buf = &packet->tc.y; 1041 x->len = 2; 1042 spi_message_add_tail(x, m); 1043 } 1044 1045 ts->msg_count++; 1046 m++; 1047 spi_message_init(m); 1048 m->context = ts; 1049 1050 if (ts->model == 7845) { 1051 x++; 1052 packet->read_x_cmd[0] = READ_X(vref); 1053 packet->read_x_cmd[1] = 0; 1054 packet->read_x_cmd[2] = 0; 1055 x->tx_buf = &packet->read_x_cmd[0]; 1056 x->rx_buf = &packet->tc.x_buf[0]; 1057 x->len = 3; 1058 spi_message_add_tail(x, m); 1059 } else { 1060 /* turn y- off, x+ on, then leave in lowpower */ 1061 x++; 1062 packet->read_x = READ_X(vref); 1063 x->tx_buf = &packet->read_x; 1064 x->len = 1; 1065 spi_message_add_tail(x, m); 1066 1067 x++; 1068 x->rx_buf = &packet->tc.x; 1069 x->len = 2; 1070 spi_message_add_tail(x, m); 1071 } 1072 1073 /* ... maybe discard first sample ... */ 1074 if (pdata->settle_delay_usecs) { 1075 x->delay.value = pdata->settle_delay_usecs; 1076 x->delay.unit = SPI_DELAY_UNIT_USECS; 1077 1078 x++; 1079 x->tx_buf = &packet->read_x; 1080 x->len = 1; 1081 spi_message_add_tail(x, m); 1082 1083 x++; 1084 x->rx_buf = &packet->tc.x; 1085 x->len = 2; 1086 spi_message_add_tail(x, m); 1087 } 1088 1089 /* turn y+ off, x- on; we'll use formula #2 */ 1090 if (ts->model == 7846) { 1091 ts->msg_count++; 1092 m++; 1093 spi_message_init(m); 1094 m->context = ts; 1095 1096 x++; 1097 packet->read_z1 = READ_Z1(vref); 1098 x->tx_buf = &packet->read_z1; 1099 x->len = 1; 1100 spi_message_add_tail(x, m); 1101 1102 x++; 1103 x->rx_buf = &packet->tc.z1; 1104 x->len = 2; 1105 spi_message_add_tail(x, m); 1106 1107 /* ... maybe discard first sample ... */ 1108 if (pdata->settle_delay_usecs) { 1109 x->delay.value = pdata->settle_delay_usecs; 1110 x->delay.unit = SPI_DELAY_UNIT_USECS; 1111 1112 x++; 1113 x->tx_buf = &packet->read_z1; 1114 x->len = 1; 1115 spi_message_add_tail(x, m); 1116 1117 x++; 1118 x->rx_buf = &packet->tc.z1; 1119 x->len = 2; 1120 spi_message_add_tail(x, m); 1121 } 1122 1123 ts->msg_count++; 1124 m++; 1125 spi_message_init(m); 1126 m->context = ts; 1127 1128 x++; 1129 packet->read_z2 = READ_Z2(vref); 1130 x->tx_buf = &packet->read_z2; 1131 x->len = 1; 1132 spi_message_add_tail(x, m); 1133 1134 x++; 1135 x->rx_buf = &packet->tc.z2; 1136 x->len = 2; 1137 spi_message_add_tail(x, m); 1138 1139 /* ... maybe discard first sample ... */ 1140 if (pdata->settle_delay_usecs) { 1141 x->delay.value = pdata->settle_delay_usecs; 1142 x->delay.unit = SPI_DELAY_UNIT_USECS; 1143 1144 x++; 1145 x->tx_buf = &packet->read_z2; 1146 x->len = 1; 1147 spi_message_add_tail(x, m); 1148 1149 x++; 1150 x->rx_buf = &packet->tc.z2; 1151 x->len = 2; 1152 spi_message_add_tail(x, m); 1153 } 1154 } 1155 1156 /* power down */ 1157 ts->msg_count++; 1158 m++; 1159 spi_message_init(m); 1160 m->context = ts; 1161 1162 if (ts->model == 7845) { 1163 x++; 1164 packet->pwrdown_cmd[0] = PWRDOWN; 1165 packet->pwrdown_cmd[1] = 0; 1166 packet->pwrdown_cmd[2] = 0; 1167 x->tx_buf = &packet->pwrdown_cmd[0]; 1168 x->len = 3; 1169 } else { 1170 x++; 1171 packet->pwrdown = PWRDOWN; 1172 x->tx_buf = &packet->pwrdown; 1173 x->len = 1; 1174 spi_message_add_tail(x, m); 1175 1176 x++; 1177 x->rx_buf = &packet->dummy; 1178 x->len = 2; 1179 } 1180 1181 CS_CHANGE(*x); 1182 spi_message_add_tail(x, m); 1183 } 1184 1185 #ifdef CONFIG_OF 1186 static const struct of_device_id ads7846_dt_ids[] = { 1187 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1188 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1189 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1190 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1191 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1192 { } 1193 }; 1194 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1195 1196 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1197 { 1198 struct ads7846_platform_data *pdata; 1199 struct device_node *node = dev->of_node; 1200 const struct of_device_id *match; 1201 u32 value; 1202 1203 if (!node) { 1204 dev_err(dev, "Device does not have associated DT data\n"); 1205 return ERR_PTR(-EINVAL); 1206 } 1207 1208 match = of_match_device(ads7846_dt_ids, dev); 1209 if (!match) { 1210 dev_err(dev, "Unknown device model\n"); 1211 return ERR_PTR(-EINVAL); 1212 } 1213 1214 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1215 if (!pdata) 1216 return ERR_PTR(-ENOMEM); 1217 1218 pdata->model = (unsigned long)match->data; 1219 1220 of_property_read_u16(node, "ti,vref-delay-usecs", 1221 &pdata->vref_delay_usecs); 1222 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1223 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1224 1225 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1226 1227 of_property_read_u16(node, "ti,settle-delay-usec", 1228 &pdata->settle_delay_usecs); 1229 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1230 &pdata->penirq_recheck_delay_usecs); 1231 1232 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1233 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1234 1235 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1236 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1237 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1238 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1239 1240 /* 1241 * touchscreen-max-pressure gets parsed during 1242 * touchscreen_parse_properties() 1243 */ 1244 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1245 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1246 pdata->pressure_min = (u16) value; 1247 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1248 1249 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1250 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1251 pdata->debounce_max = (u16) value; 1252 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1253 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1254 1255 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1256 &pdata->gpio_pendown_debounce); 1257 1258 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1259 of_property_read_bool(node, "linux,wakeup"); 1260 1261 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1262 1263 return pdata; 1264 } 1265 #else 1266 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1267 { 1268 dev_err(dev, "no platform data defined\n"); 1269 return ERR_PTR(-EINVAL); 1270 } 1271 #endif 1272 1273 static int ads7846_probe(struct spi_device *spi) 1274 { 1275 const struct ads7846_platform_data *pdata; 1276 struct ads7846 *ts; 1277 struct ads7846_packet *packet; 1278 struct input_dev *input_dev; 1279 unsigned long irq_flags; 1280 int err; 1281 1282 if (!spi->irq) { 1283 dev_dbg(&spi->dev, "no IRQ?\n"); 1284 return -EINVAL; 1285 } 1286 1287 /* don't exceed max specified sample rate */ 1288 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1289 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1290 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1291 return -EINVAL; 1292 } 1293 1294 /* 1295 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1296 * that even if the hardware can do that, the SPI controller driver 1297 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1298 */ 1299 spi->bits_per_word = 8; 1300 spi->mode = SPI_MODE_0; 1301 err = spi_setup(spi); 1302 if (err < 0) 1303 return err; 1304 1305 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1306 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1307 input_dev = input_allocate_device(); 1308 if (!ts || !packet || !input_dev) { 1309 err = -ENOMEM; 1310 goto err_free_mem; 1311 } 1312 1313 spi_set_drvdata(spi, ts); 1314 1315 ts->packet = packet; 1316 ts->spi = spi; 1317 ts->input = input_dev; 1318 1319 mutex_init(&ts->lock); 1320 init_waitqueue_head(&ts->wait); 1321 1322 pdata = dev_get_platdata(&spi->dev); 1323 if (!pdata) { 1324 pdata = ads7846_probe_dt(&spi->dev); 1325 if (IS_ERR(pdata)) { 1326 err = PTR_ERR(pdata); 1327 goto err_free_mem; 1328 } 1329 } 1330 1331 ts->model = pdata->model ? : 7846; 1332 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1333 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1334 ts->vref_mv = pdata->vref_mv; 1335 1336 if (pdata->filter != NULL) { 1337 if (pdata->filter_init != NULL) { 1338 err = pdata->filter_init(pdata, &ts->filter_data); 1339 if (err < 0) 1340 goto err_free_mem; 1341 } 1342 ts->filter = pdata->filter; 1343 ts->filter_cleanup = pdata->filter_cleanup; 1344 } else if (pdata->debounce_max) { 1345 ts->debounce_max = pdata->debounce_max; 1346 if (ts->debounce_max < 2) 1347 ts->debounce_max = 2; 1348 ts->debounce_tol = pdata->debounce_tol; 1349 ts->debounce_rep = pdata->debounce_rep; 1350 ts->filter = ads7846_debounce_filter; 1351 ts->filter_data = ts; 1352 } else { 1353 ts->filter = ads7846_no_filter; 1354 } 1355 1356 err = ads7846_setup_pendown(spi, ts, pdata); 1357 if (err) 1358 goto err_cleanup_filter; 1359 1360 if (pdata->penirq_recheck_delay_usecs) 1361 ts->penirq_recheck_delay_usecs = 1362 pdata->penirq_recheck_delay_usecs; 1363 1364 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1365 1366 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1367 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1368 1369 input_dev->name = ts->name; 1370 input_dev->phys = ts->phys; 1371 input_dev->dev.parent = &spi->dev; 1372 1373 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1374 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1375 input_set_abs_params(input_dev, ABS_X, 1376 pdata->x_min ? : 0, 1377 pdata->x_max ? : MAX_12BIT, 1378 0, 0); 1379 input_set_abs_params(input_dev, ABS_Y, 1380 pdata->y_min ? : 0, 1381 pdata->y_max ? : MAX_12BIT, 1382 0, 0); 1383 input_set_abs_params(input_dev, ABS_PRESSURE, 1384 pdata->pressure_min, pdata->pressure_max, 0, 0); 1385 1386 /* 1387 * Parse common framework properties. Must be done here to ensure the 1388 * correct behaviour in case of using the legacy vendor bindings. The 1389 * general binding value overrides the vendor specific one. 1390 */ 1391 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1392 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1393 1394 /* 1395 * Check if legacy ti,swap-xy binding is used instead of 1396 * touchscreen-swapped-x-y 1397 */ 1398 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1399 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1400 ts->core_prop.swap_x_y = true; 1401 } 1402 1403 ads7846_setup_spi_msg(ts, pdata); 1404 1405 ts->reg = regulator_get(&spi->dev, "vcc"); 1406 if (IS_ERR(ts->reg)) { 1407 err = PTR_ERR(ts->reg); 1408 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1409 goto err_free_gpio; 1410 } 1411 1412 err = regulator_enable(ts->reg); 1413 if (err) { 1414 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1415 goto err_put_regulator; 1416 } 1417 1418 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1419 irq_flags |= IRQF_ONESHOT; 1420 1421 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1422 irq_flags, spi->dev.driver->name, ts); 1423 if (err && !pdata->irq_flags) { 1424 dev_info(&spi->dev, 1425 "trying pin change workaround on irq %d\n", spi->irq); 1426 irq_flags |= IRQF_TRIGGER_RISING; 1427 err = request_threaded_irq(spi->irq, 1428 ads7846_hard_irq, ads7846_irq, 1429 irq_flags, spi->dev.driver->name, ts); 1430 } 1431 1432 if (err) { 1433 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1434 goto err_disable_regulator; 1435 } 1436 1437 err = ads784x_hwmon_register(spi, ts); 1438 if (err) 1439 goto err_free_irq; 1440 1441 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1442 1443 /* 1444 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1445 * the touchscreen, in case it's not connected. 1446 */ 1447 if (ts->model == 7845) 1448 ads7845_read12_ser(&spi->dev, PWRDOWN); 1449 else 1450 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1451 1452 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1453 if (err) 1454 goto err_remove_hwmon; 1455 1456 err = input_register_device(input_dev); 1457 if (err) 1458 goto err_remove_attr_group; 1459 1460 device_init_wakeup(&spi->dev, pdata->wakeup); 1461 1462 /* 1463 * If device does not carry platform data we must have allocated it 1464 * when parsing DT data. 1465 */ 1466 if (!dev_get_platdata(&spi->dev)) 1467 devm_kfree(&spi->dev, (void *)pdata); 1468 1469 return 0; 1470 1471 err_remove_attr_group: 1472 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1473 err_remove_hwmon: 1474 ads784x_hwmon_unregister(spi, ts); 1475 err_free_irq: 1476 free_irq(spi->irq, ts); 1477 err_disable_regulator: 1478 regulator_disable(ts->reg); 1479 err_put_regulator: 1480 regulator_put(ts->reg); 1481 err_free_gpio: 1482 if (!ts->get_pendown_state) 1483 gpio_free(ts->gpio_pendown); 1484 err_cleanup_filter: 1485 if (ts->filter_cleanup) 1486 ts->filter_cleanup(ts->filter_data); 1487 err_free_mem: 1488 input_free_device(input_dev); 1489 kfree(packet); 1490 kfree(ts); 1491 return err; 1492 } 1493 1494 static int ads7846_remove(struct spi_device *spi) 1495 { 1496 struct ads7846 *ts = spi_get_drvdata(spi); 1497 1498 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1499 1500 ads7846_disable(ts); 1501 free_irq(ts->spi->irq, ts); 1502 1503 input_unregister_device(ts->input); 1504 1505 ads784x_hwmon_unregister(spi, ts); 1506 1507 regulator_put(ts->reg); 1508 1509 if (!ts->get_pendown_state) { 1510 /* 1511 * If we are not using specialized pendown method we must 1512 * have been relying on gpio we set up ourselves. 1513 */ 1514 gpio_free(ts->gpio_pendown); 1515 } 1516 1517 if (ts->filter_cleanup) 1518 ts->filter_cleanup(ts->filter_data); 1519 1520 kfree(ts->packet); 1521 kfree(ts); 1522 1523 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1524 1525 return 0; 1526 } 1527 1528 static struct spi_driver ads7846_driver = { 1529 .driver = { 1530 .name = "ads7846", 1531 .pm = &ads7846_pm, 1532 .of_match_table = of_match_ptr(ads7846_dt_ids), 1533 }, 1534 .probe = ads7846_probe, 1535 .remove = ads7846_remove, 1536 }; 1537 1538 module_spi_driver(ads7846_driver); 1539 1540 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1541 MODULE_LICENSE("GPL"); 1542 MODULE_ALIAS("spi:ads7846"); 1543