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 #include <asm/unaligned.h> 37 38 /* 39 * This code has been heavily tested on a Nokia 770, and lightly 40 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 41 * TSC2046 is just newer ads7846 silicon. 42 * Support for ads7843 tested on Atmel at91sam926x-EK. 43 * Support for ads7845 has only been stubbed in. 44 * Support for Analog Devices AD7873 and AD7843 tested. 45 * 46 * IRQ handling needs a workaround because of a shortcoming in handling 47 * edge triggered IRQs on some platforms like the OMAP1/2. These 48 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 49 * have to maintain our own SW IRQ disabled status. This should be 50 * removed as soon as the affected platform's IRQ handling is fixed. 51 * 52 * App note sbaa036 talks in more detail about accurate sampling... 53 * that ought to help in situations like LCDs inducing noise (which 54 * can also be helped by using synch signals) and more generally. 55 * This driver tries to utilize the measures described in the app 56 * note. The strength of filtering can be set in the board-* specific 57 * files. 58 */ 59 60 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 61 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 62 63 /* this driver doesn't aim at the peak continuous sample rate */ 64 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 65 66 struct ts_event { 67 /* 68 * For portability, we can't read 12 bit values using SPI (which 69 * would make the controller deliver them as native byte order u16 70 * with msbs zeroed). Instead, we read them as two 8-bit values, 71 * *** WHICH NEED BYTESWAPPING *** and range adjustment. 72 */ 73 u16 x; 74 u16 y; 75 u16 z1, z2; 76 bool ignore; 77 u8 x_buf[3]; 78 u8 y_buf[3]; 79 }; 80 81 /* 82 * We allocate this separately to avoid cache line sharing issues when 83 * driver is used with DMA-based SPI controllers (like atmel_spi) on 84 * systems where main memory is not DMA-coherent (most non-x86 boards). 85 */ 86 struct ads7846_packet { 87 u8 read_x, read_y, read_z1, read_z2, pwrdown; 88 u16 dummy; /* for the pwrdown read */ 89 struct ts_event tc; 90 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ 91 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; 92 }; 93 94 struct ads7846 { 95 struct input_dev *input; 96 char phys[32]; 97 char name[32]; 98 99 struct spi_device *spi; 100 struct regulator *reg; 101 102 #if IS_ENABLED(CONFIG_HWMON) 103 struct device *hwmon; 104 #endif 105 106 u16 model; 107 u16 vref_mv; 108 u16 vref_delay_usecs; 109 u16 x_plate_ohms; 110 u16 pressure_max; 111 112 bool swap_xy; 113 bool use_internal; 114 115 struct ads7846_packet *packet; 116 117 struct spi_transfer xfer[18]; 118 struct spi_message msg[5]; 119 int msg_count; 120 wait_queue_head_t wait; 121 122 bool pendown; 123 124 int read_cnt; 125 int read_rep; 126 int last_read; 127 128 u16 debounce_max; 129 u16 debounce_tol; 130 u16 debounce_rep; 131 132 u16 penirq_recheck_delay_usecs; 133 134 struct touchscreen_properties core_prop; 135 136 struct mutex lock; 137 bool stopped; /* P: lock */ 138 bool disabled; /* P: lock */ 139 bool suspended; /* P: lock */ 140 141 int (*filter)(void *data, int data_idx, int *val); 142 void *filter_data; 143 void (*filter_cleanup)(void *data); 144 int (*get_pendown_state)(void); 145 int gpio_pendown; 146 147 void (*wait_for_sync)(void); 148 }; 149 150 /* leave chip selected when we're done, for quicker re-select? */ 151 #if 0 152 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 153 #else 154 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 155 #endif 156 157 /*--------------------------------------------------------------------------*/ 158 159 /* The ADS7846 has touchscreen and other sensors. 160 * Earlier ads784x chips are somewhat compatible. 161 */ 162 #define ADS_START (1 << 7) 163 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 164 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 165 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 166 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 167 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 168 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 169 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 170 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 171 #define ADS_8_BIT (1 << 3) 172 #define ADS_12_BIT (0 << 3) 173 #define ADS_SER (1 << 2) /* non-differential */ 174 #define ADS_DFR (0 << 2) /* differential */ 175 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 176 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 177 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 178 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 179 180 #define MAX_12BIT ((1<<12)-1) 181 182 /* leave ADC powered up (disables penirq) between differential samples */ 183 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 184 | ADS_12_BIT | ADS_DFR | \ 185 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 186 187 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 188 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 189 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 190 191 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 192 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 193 194 /* single-ended samples need to first power up reference voltage; 195 * we leave both ADC and VREF powered 196 */ 197 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 198 | ADS_12_BIT | ADS_SER) 199 200 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 201 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 202 203 static int get_pendown_state(struct ads7846 *ts) 204 { 205 if (ts->get_pendown_state) 206 return ts->get_pendown_state(); 207 208 return !gpio_get_value(ts->gpio_pendown); 209 } 210 211 static void ads7846_report_pen_up(struct ads7846 *ts) 212 { 213 struct input_dev *input = ts->input; 214 215 input_report_key(input, BTN_TOUCH, 0); 216 input_report_abs(input, ABS_PRESSURE, 0); 217 input_sync(input); 218 219 ts->pendown = false; 220 dev_vdbg(&ts->spi->dev, "UP\n"); 221 } 222 223 /* Must be called with ts->lock held */ 224 static void ads7846_stop(struct ads7846 *ts) 225 { 226 if (!ts->disabled && !ts->suspended) { 227 /* Signal IRQ thread to stop polling and disable the handler. */ 228 ts->stopped = true; 229 mb(); 230 wake_up(&ts->wait); 231 disable_irq(ts->spi->irq); 232 } 233 } 234 235 /* Must be called with ts->lock held */ 236 static void ads7846_restart(struct ads7846 *ts) 237 { 238 if (!ts->disabled && !ts->suspended) { 239 /* Check if pen was released since last stop */ 240 if (ts->pendown && !get_pendown_state(ts)) 241 ads7846_report_pen_up(ts); 242 243 /* Tell IRQ thread that it may poll the device. */ 244 ts->stopped = false; 245 mb(); 246 enable_irq(ts->spi->irq); 247 } 248 } 249 250 /* Must be called with ts->lock held */ 251 static void __ads7846_disable(struct ads7846 *ts) 252 { 253 ads7846_stop(ts); 254 regulator_disable(ts->reg); 255 256 /* 257 * We know the chip's in low power mode since we always 258 * leave it that way after every request 259 */ 260 } 261 262 /* Must be called with ts->lock held */ 263 static void __ads7846_enable(struct ads7846 *ts) 264 { 265 int error; 266 267 error = regulator_enable(ts->reg); 268 if (error != 0) 269 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 270 271 ads7846_restart(ts); 272 } 273 274 static void ads7846_disable(struct ads7846 *ts) 275 { 276 mutex_lock(&ts->lock); 277 278 if (!ts->disabled) { 279 280 if (!ts->suspended) 281 __ads7846_disable(ts); 282 283 ts->disabled = true; 284 } 285 286 mutex_unlock(&ts->lock); 287 } 288 289 static void ads7846_enable(struct ads7846 *ts) 290 { 291 mutex_lock(&ts->lock); 292 293 if (ts->disabled) { 294 295 ts->disabled = false; 296 297 if (!ts->suspended) 298 __ads7846_enable(ts); 299 } 300 301 mutex_unlock(&ts->lock); 302 } 303 304 /*--------------------------------------------------------------------------*/ 305 306 /* 307 * Non-touchscreen sensors only use single-ended conversions. 308 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 309 * ads7846 lets that pin be unconnected, to use internal vREF. 310 */ 311 312 struct ser_req { 313 u8 ref_on; 314 u8 command; 315 u8 ref_off; 316 u16 scratch; 317 struct spi_message msg; 318 struct spi_transfer xfer[6]; 319 /* 320 * DMA (thus cache coherency maintenance) requires the 321 * transfer buffers to live in their own cache lines. 322 */ 323 __be16 sample ____cacheline_aligned; 324 }; 325 326 struct ads7845_ser_req { 327 u8 command[3]; 328 struct spi_message msg; 329 struct spi_transfer xfer[2]; 330 /* 331 * DMA (thus cache coherency maintenance) requires the 332 * transfer buffers to live in their own cache lines. 333 */ 334 u8 sample[3] ____cacheline_aligned; 335 }; 336 337 static int ads7846_read12_ser(struct device *dev, unsigned command) 338 { 339 struct spi_device *spi = to_spi_device(dev); 340 struct ads7846 *ts = dev_get_drvdata(dev); 341 struct ser_req *req; 342 int status; 343 344 req = kzalloc(sizeof *req, GFP_KERNEL); 345 if (!req) 346 return -ENOMEM; 347 348 spi_message_init(&req->msg); 349 350 /* maybe turn on internal vREF, and let it settle */ 351 if (ts->use_internal) { 352 req->ref_on = REF_ON; 353 req->xfer[0].tx_buf = &req->ref_on; 354 req->xfer[0].len = 1; 355 spi_message_add_tail(&req->xfer[0], &req->msg); 356 357 req->xfer[1].rx_buf = &req->scratch; 358 req->xfer[1].len = 2; 359 360 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 361 req->xfer[1].delay.value = ts->vref_delay_usecs; 362 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 363 spi_message_add_tail(&req->xfer[1], &req->msg); 364 365 /* Enable reference voltage */ 366 command |= ADS_PD10_REF_ON; 367 } 368 369 /* Enable ADC in every case */ 370 command |= ADS_PD10_ADC_ON; 371 372 /* take sample */ 373 req->command = (u8) command; 374 req->xfer[2].tx_buf = &req->command; 375 req->xfer[2].len = 1; 376 spi_message_add_tail(&req->xfer[2], &req->msg); 377 378 req->xfer[3].rx_buf = &req->sample; 379 req->xfer[3].len = 2; 380 spi_message_add_tail(&req->xfer[3], &req->msg); 381 382 /* REVISIT: take a few more samples, and compare ... */ 383 384 /* converter in low power mode & enable PENIRQ */ 385 req->ref_off = PWRDOWN; 386 req->xfer[4].tx_buf = &req->ref_off; 387 req->xfer[4].len = 1; 388 spi_message_add_tail(&req->xfer[4], &req->msg); 389 390 req->xfer[5].rx_buf = &req->scratch; 391 req->xfer[5].len = 2; 392 CS_CHANGE(req->xfer[5]); 393 spi_message_add_tail(&req->xfer[5], &req->msg); 394 395 mutex_lock(&ts->lock); 396 ads7846_stop(ts); 397 status = spi_sync(spi, &req->msg); 398 ads7846_restart(ts); 399 mutex_unlock(&ts->lock); 400 401 if (status == 0) { 402 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 403 status = be16_to_cpu(req->sample); 404 status = status >> 3; 405 status &= 0x0fff; 406 } 407 408 kfree(req); 409 return status; 410 } 411 412 static int ads7845_read12_ser(struct device *dev, unsigned command) 413 { 414 struct spi_device *spi = to_spi_device(dev); 415 struct ads7846 *ts = dev_get_drvdata(dev); 416 struct ads7845_ser_req *req; 417 int status; 418 419 req = kzalloc(sizeof *req, GFP_KERNEL); 420 if (!req) 421 return -ENOMEM; 422 423 spi_message_init(&req->msg); 424 425 req->command[0] = (u8) command; 426 req->xfer[0].tx_buf = req->command; 427 req->xfer[0].rx_buf = req->sample; 428 req->xfer[0].len = 3; 429 spi_message_add_tail(&req->xfer[0], &req->msg); 430 431 mutex_lock(&ts->lock); 432 ads7846_stop(ts); 433 status = spi_sync(spi, &req->msg); 434 ads7846_restart(ts); 435 mutex_unlock(&ts->lock); 436 437 if (status == 0) { 438 /* BE12 value, then padding */ 439 status = get_unaligned_be16(&req->sample[1]); 440 status = status >> 3; 441 status &= 0x0fff; 442 } 443 444 kfree(req); 445 return status; 446 } 447 448 #if IS_ENABLED(CONFIG_HWMON) 449 450 #define SHOW(name, var, adjust) static ssize_t \ 451 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 452 { \ 453 struct ads7846 *ts = dev_get_drvdata(dev); \ 454 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 455 READ_12BIT_SER(var)); \ 456 if (v < 0) \ 457 return v; \ 458 return sprintf(buf, "%u\n", adjust(ts, v)); \ 459 } \ 460 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 461 462 463 /* Sysfs conventions report temperatures in millidegrees Celsius. 464 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 465 * accuracy scheme without calibration data. For now we won't try either; 466 * userspace sees raw sensor values, and must scale/calibrate appropriately. 467 */ 468 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 469 { 470 return v; 471 } 472 473 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 474 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 475 476 477 /* sysfs conventions report voltages in millivolts. We can convert voltages 478 * if we know vREF. userspace may need to scale vAUX to match the board's 479 * external resistors; we assume that vBATT only uses the internal ones. 480 */ 481 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 482 { 483 unsigned retval = v; 484 485 /* external resistors may scale vAUX into 0..vREF */ 486 retval *= ts->vref_mv; 487 retval = retval >> 12; 488 489 return retval; 490 } 491 492 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 493 { 494 unsigned retval = vaux_adjust(ts, v); 495 496 /* ads7846 has a resistor ladder to scale this signal down */ 497 if (ts->model == 7846) 498 retval *= 4; 499 500 return retval; 501 } 502 503 SHOW(in0_input, vaux, vaux_adjust) 504 SHOW(in1_input, vbatt, vbatt_adjust) 505 506 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 507 int index) 508 { 509 struct device *dev = container_of(kobj, struct device, kobj); 510 struct ads7846 *ts = dev_get_drvdata(dev); 511 512 if (ts->model == 7843 && index < 2) /* in0, in1 */ 513 return 0; 514 if (ts->model == 7845 && index != 2) /* in0 */ 515 return 0; 516 517 return attr->mode; 518 } 519 520 static struct attribute *ads7846_attributes[] = { 521 &dev_attr_temp0.attr, /* 0 */ 522 &dev_attr_temp1.attr, /* 1 */ 523 &dev_attr_in0_input.attr, /* 2 */ 524 &dev_attr_in1_input.attr, /* 3 */ 525 NULL, 526 }; 527 528 static const struct attribute_group ads7846_attr_group = { 529 .attrs = ads7846_attributes, 530 .is_visible = ads7846_is_visible, 531 }; 532 __ATTRIBUTE_GROUPS(ads7846_attr); 533 534 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 535 { 536 /* hwmon sensors need a reference voltage */ 537 switch (ts->model) { 538 case 7846: 539 if (!ts->vref_mv) { 540 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 541 ts->vref_mv = 2500; 542 ts->use_internal = true; 543 } 544 break; 545 case 7845: 546 case 7843: 547 if (!ts->vref_mv) { 548 dev_warn(&spi->dev, 549 "external vREF for ADS%d not specified\n", 550 ts->model); 551 return 0; 552 } 553 break; 554 } 555 556 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 557 ts, ads7846_attr_groups); 558 559 return PTR_ERR_OR_ZERO(ts->hwmon); 560 } 561 562 static void ads784x_hwmon_unregister(struct spi_device *spi, 563 struct ads7846 *ts) 564 { 565 if (ts->hwmon) 566 hwmon_device_unregister(ts->hwmon); 567 } 568 569 #else 570 static inline int ads784x_hwmon_register(struct spi_device *spi, 571 struct ads7846 *ts) 572 { 573 return 0; 574 } 575 576 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 577 struct ads7846 *ts) 578 { 579 } 580 #endif 581 582 static ssize_t ads7846_pen_down_show(struct device *dev, 583 struct device_attribute *attr, char *buf) 584 { 585 struct ads7846 *ts = dev_get_drvdata(dev); 586 587 return sprintf(buf, "%u\n", ts->pendown); 588 } 589 590 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 591 592 static ssize_t ads7846_disable_show(struct device *dev, 593 struct device_attribute *attr, char *buf) 594 { 595 struct ads7846 *ts = dev_get_drvdata(dev); 596 597 return sprintf(buf, "%u\n", ts->disabled); 598 } 599 600 static ssize_t ads7846_disable_store(struct device *dev, 601 struct device_attribute *attr, 602 const char *buf, size_t count) 603 { 604 struct ads7846 *ts = dev_get_drvdata(dev); 605 unsigned int i; 606 int err; 607 608 err = kstrtouint(buf, 10, &i); 609 if (err) 610 return err; 611 612 if (i) 613 ads7846_disable(ts); 614 else 615 ads7846_enable(ts); 616 617 return count; 618 } 619 620 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 621 622 static struct attribute *ads784x_attributes[] = { 623 &dev_attr_pen_down.attr, 624 &dev_attr_disable.attr, 625 NULL, 626 }; 627 628 static const struct attribute_group ads784x_attr_group = { 629 .attrs = ads784x_attributes, 630 }; 631 632 /*--------------------------------------------------------------------------*/ 633 634 static void null_wait_for_sync(void) 635 { 636 } 637 638 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 639 { 640 struct ads7846 *ts = ads; 641 642 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 643 /* Start over collecting consistent readings. */ 644 ts->read_rep = 0; 645 /* 646 * Repeat it, if this was the first read or the read 647 * wasn't consistent enough. 648 */ 649 if (ts->read_cnt < ts->debounce_max) { 650 ts->last_read = *val; 651 ts->read_cnt++; 652 return ADS7846_FILTER_REPEAT; 653 } else { 654 /* 655 * Maximum number of debouncing reached and still 656 * not enough number of consistent readings. Abort 657 * the whole sample, repeat it in the next sampling 658 * period. 659 */ 660 ts->read_cnt = 0; 661 return ADS7846_FILTER_IGNORE; 662 } 663 } else { 664 if (++ts->read_rep > ts->debounce_rep) { 665 /* 666 * Got a good reading for this coordinate, 667 * go for the next one. 668 */ 669 ts->read_cnt = 0; 670 ts->read_rep = 0; 671 return ADS7846_FILTER_OK; 672 } else { 673 /* Read more values that are consistent. */ 674 ts->read_cnt++; 675 return ADS7846_FILTER_REPEAT; 676 } 677 } 678 } 679 680 static int ads7846_no_filter(void *ads, int data_idx, int *val) 681 { 682 return ADS7846_FILTER_OK; 683 } 684 685 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 686 { 687 int value; 688 struct spi_transfer *t = 689 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 690 691 if (ts->model == 7845) { 692 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); 693 } else { 694 /* 695 * adjust: on-wire is a must-ignore bit, a BE12 value, then 696 * padding; built from two 8 bit values written msb-first. 697 */ 698 value = be16_to_cpup((__be16 *)t->rx_buf); 699 } 700 701 /* enforce ADC output is 12 bits width */ 702 return (value >> 3) & 0xfff; 703 } 704 705 static void ads7846_update_value(struct spi_message *m, int val) 706 { 707 struct spi_transfer *t = 708 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 709 710 *(u16 *)t->rx_buf = val; 711 } 712 713 static void ads7846_read_state(struct ads7846 *ts) 714 { 715 struct ads7846_packet *packet = ts->packet; 716 struct spi_message *m; 717 int msg_idx = 0; 718 int val; 719 int action; 720 int error; 721 722 while (msg_idx < ts->msg_count) { 723 724 ts->wait_for_sync(); 725 726 m = &ts->msg[msg_idx]; 727 error = spi_sync(ts->spi, m); 728 if (error) { 729 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 730 packet->tc.ignore = true; 731 return; 732 } 733 734 /* 735 * Last message is power down request, no need to convert 736 * or filter the value. 737 */ 738 if (msg_idx < ts->msg_count - 1) { 739 740 val = ads7846_get_value(ts, m); 741 742 action = ts->filter(ts->filter_data, msg_idx, &val); 743 switch (action) { 744 case ADS7846_FILTER_REPEAT: 745 continue; 746 747 case ADS7846_FILTER_IGNORE: 748 packet->tc.ignore = true; 749 msg_idx = ts->msg_count - 1; 750 continue; 751 752 case ADS7846_FILTER_OK: 753 ads7846_update_value(m, val); 754 packet->tc.ignore = false; 755 msg_idx++; 756 break; 757 758 default: 759 BUG(); 760 } 761 } else { 762 msg_idx++; 763 } 764 } 765 } 766 767 static void ads7846_report_state(struct ads7846 *ts) 768 { 769 struct ads7846_packet *packet = ts->packet; 770 unsigned int Rt; 771 u16 x, y, z1, z2; 772 773 /* 774 * ads7846_get_value() does in-place conversion (including byte swap) 775 * from on-the-wire format as part of debouncing to get stable 776 * readings. 777 */ 778 if (ts->model == 7845) { 779 x = *(u16 *)packet->tc.x_buf; 780 y = *(u16 *)packet->tc.y_buf; 781 z1 = 0; 782 z2 = 0; 783 } else { 784 x = packet->tc.x; 785 y = packet->tc.y; 786 z1 = packet->tc.z1; 787 z2 = packet->tc.z2; 788 } 789 790 /* range filtering */ 791 if (x == MAX_12BIT) 792 x = 0; 793 794 if (ts->model == 7843) { 795 Rt = ts->pressure_max / 2; 796 } else if (ts->model == 7845) { 797 if (get_pendown_state(ts)) 798 Rt = ts->pressure_max / 2; 799 else 800 Rt = 0; 801 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 802 } else if (likely(x && z1)) { 803 /* compute touch pressure resistance using equation #2 */ 804 Rt = z2; 805 Rt -= z1; 806 Rt *= ts->x_plate_ohms; 807 Rt = DIV_ROUND_CLOSEST(Rt, 16); 808 Rt *= x; 809 Rt /= z1; 810 Rt = DIV_ROUND_CLOSEST(Rt, 256); 811 } else { 812 Rt = 0; 813 } 814 815 /* 816 * Sample found inconsistent by debouncing or pressure is beyond 817 * the maximum. Don't report it to user space, repeat at least 818 * once more the measurement 819 */ 820 if (packet->tc.ignore || Rt > ts->pressure_max) { 821 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 822 packet->tc.ignore, Rt); 823 return; 824 } 825 826 /* 827 * Maybe check the pendown state before reporting. This discards 828 * false readings when the pen is lifted. 829 */ 830 if (ts->penirq_recheck_delay_usecs) { 831 udelay(ts->penirq_recheck_delay_usecs); 832 if (!get_pendown_state(ts)) 833 Rt = 0; 834 } 835 836 /* 837 * NOTE: We can't rely on the pressure to determine the pen down 838 * state, even this controller has a pressure sensor. The pressure 839 * value can fluctuate for quite a while after lifting the pen and 840 * in some cases may not even settle at the expected value. 841 * 842 * The only safe way to check for the pen up condition is in the 843 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 844 */ 845 if (Rt) { 846 struct input_dev *input = ts->input; 847 848 if (!ts->pendown) { 849 input_report_key(input, BTN_TOUCH, 1); 850 ts->pendown = true; 851 dev_vdbg(&ts->spi->dev, "DOWN\n"); 852 } 853 854 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 855 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 856 857 input_sync(input); 858 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 859 } 860 } 861 862 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 863 { 864 struct ads7846 *ts = handle; 865 866 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 867 } 868 869 870 static irqreturn_t ads7846_irq(int irq, void *handle) 871 { 872 struct ads7846 *ts = handle; 873 874 /* Start with a small delay before checking pendown state */ 875 msleep(TS_POLL_DELAY); 876 877 while (!ts->stopped && get_pendown_state(ts)) { 878 879 /* pen is down, continue with the measurement */ 880 ads7846_read_state(ts); 881 882 if (!ts->stopped) 883 ads7846_report_state(ts); 884 885 wait_event_timeout(ts->wait, ts->stopped, 886 msecs_to_jiffies(TS_POLL_PERIOD)); 887 } 888 889 if (ts->pendown && !ts->stopped) 890 ads7846_report_pen_up(ts); 891 892 return IRQ_HANDLED; 893 } 894 895 static int __maybe_unused ads7846_suspend(struct device *dev) 896 { 897 struct ads7846 *ts = dev_get_drvdata(dev); 898 899 mutex_lock(&ts->lock); 900 901 if (!ts->suspended) { 902 903 if (!ts->disabled) 904 __ads7846_disable(ts); 905 906 if (device_may_wakeup(&ts->spi->dev)) 907 enable_irq_wake(ts->spi->irq); 908 909 ts->suspended = true; 910 } 911 912 mutex_unlock(&ts->lock); 913 914 return 0; 915 } 916 917 static int __maybe_unused ads7846_resume(struct device *dev) 918 { 919 struct ads7846 *ts = dev_get_drvdata(dev); 920 921 mutex_lock(&ts->lock); 922 923 if (ts->suspended) { 924 925 ts->suspended = false; 926 927 if (device_may_wakeup(&ts->spi->dev)) 928 disable_irq_wake(ts->spi->irq); 929 930 if (!ts->disabled) 931 __ads7846_enable(ts); 932 } 933 934 mutex_unlock(&ts->lock); 935 936 return 0; 937 } 938 939 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 940 941 static int ads7846_setup_pendown(struct spi_device *spi, 942 struct ads7846 *ts, 943 const struct ads7846_platform_data *pdata) 944 { 945 int err; 946 947 /* 948 * REVISIT when the irq can be triggered active-low, or if for some 949 * reason the touchscreen isn't hooked up, we don't need to access 950 * the pendown state. 951 */ 952 953 if (pdata->get_pendown_state) { 954 ts->get_pendown_state = pdata->get_pendown_state; 955 } else if (gpio_is_valid(pdata->gpio_pendown)) { 956 957 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 958 "ads7846_pendown"); 959 if (err) { 960 dev_err(&spi->dev, 961 "failed to request/setup pendown GPIO%d: %d\n", 962 pdata->gpio_pendown, err); 963 return err; 964 } 965 966 ts->gpio_pendown = pdata->gpio_pendown; 967 968 if (pdata->gpio_pendown_debounce) 969 gpio_set_debounce(pdata->gpio_pendown, 970 pdata->gpio_pendown_debounce); 971 } else { 972 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 973 return -EINVAL; 974 } 975 976 return 0; 977 } 978 979 /* 980 * Set up the transfers to read touchscreen state; this assumes we 981 * use formula #2 for pressure, not #3. 982 */ 983 static void ads7846_setup_spi_msg(struct ads7846 *ts, 984 const struct ads7846_platform_data *pdata) 985 { 986 struct spi_message *m = &ts->msg[0]; 987 struct spi_transfer *x = ts->xfer; 988 struct ads7846_packet *packet = ts->packet; 989 int vref = pdata->keep_vref_on; 990 991 if (ts->model == 7873) { 992 /* 993 * The AD7873 is almost identical to the ADS7846 994 * keep VREF off during differential/ratiometric 995 * conversion modes. 996 */ 997 ts->model = 7846; 998 vref = 0; 999 } 1000 1001 ts->msg_count = 1; 1002 spi_message_init(m); 1003 m->context = ts; 1004 1005 if (ts->model == 7845) { 1006 packet->read_y_cmd[0] = READ_Y(vref); 1007 packet->read_y_cmd[1] = 0; 1008 packet->read_y_cmd[2] = 0; 1009 x->tx_buf = &packet->read_y_cmd[0]; 1010 x->rx_buf = &packet->tc.y_buf[0]; 1011 x->len = 3; 1012 spi_message_add_tail(x, m); 1013 } else { 1014 /* y- still on; turn on only y+ (and ADC) */ 1015 packet->read_y = READ_Y(vref); 1016 x->tx_buf = &packet->read_y; 1017 x->len = 1; 1018 spi_message_add_tail(x, m); 1019 1020 x++; 1021 x->rx_buf = &packet->tc.y; 1022 x->len = 2; 1023 spi_message_add_tail(x, m); 1024 } 1025 1026 /* 1027 * The first sample after switching drivers can be low quality; 1028 * optionally discard it, using a second one after the signals 1029 * have had enough time to stabilize. 1030 */ 1031 if (pdata->settle_delay_usecs) { 1032 x->delay.value = pdata->settle_delay_usecs; 1033 x->delay.unit = SPI_DELAY_UNIT_USECS; 1034 1035 x++; 1036 x->tx_buf = &packet->read_y; 1037 x->len = 1; 1038 spi_message_add_tail(x, m); 1039 1040 x++; 1041 x->rx_buf = &packet->tc.y; 1042 x->len = 2; 1043 spi_message_add_tail(x, m); 1044 } 1045 1046 ts->msg_count++; 1047 m++; 1048 spi_message_init(m); 1049 m->context = ts; 1050 1051 if (ts->model == 7845) { 1052 x++; 1053 packet->read_x_cmd[0] = READ_X(vref); 1054 packet->read_x_cmd[1] = 0; 1055 packet->read_x_cmd[2] = 0; 1056 x->tx_buf = &packet->read_x_cmd[0]; 1057 x->rx_buf = &packet->tc.x_buf[0]; 1058 x->len = 3; 1059 spi_message_add_tail(x, m); 1060 } else { 1061 /* turn y- off, x+ on, then leave in lowpower */ 1062 x++; 1063 packet->read_x = READ_X(vref); 1064 x->tx_buf = &packet->read_x; 1065 x->len = 1; 1066 spi_message_add_tail(x, m); 1067 1068 x++; 1069 x->rx_buf = &packet->tc.x; 1070 x->len = 2; 1071 spi_message_add_tail(x, m); 1072 } 1073 1074 /* ... maybe discard first sample ... */ 1075 if (pdata->settle_delay_usecs) { 1076 x->delay.value = pdata->settle_delay_usecs; 1077 x->delay.unit = SPI_DELAY_UNIT_USECS; 1078 1079 x++; 1080 x->tx_buf = &packet->read_x; 1081 x->len = 1; 1082 spi_message_add_tail(x, m); 1083 1084 x++; 1085 x->rx_buf = &packet->tc.x; 1086 x->len = 2; 1087 spi_message_add_tail(x, m); 1088 } 1089 1090 /* turn y+ off, x- on; we'll use formula #2 */ 1091 if (ts->model == 7846) { 1092 ts->msg_count++; 1093 m++; 1094 spi_message_init(m); 1095 m->context = ts; 1096 1097 x++; 1098 packet->read_z1 = READ_Z1(vref); 1099 x->tx_buf = &packet->read_z1; 1100 x->len = 1; 1101 spi_message_add_tail(x, m); 1102 1103 x++; 1104 x->rx_buf = &packet->tc.z1; 1105 x->len = 2; 1106 spi_message_add_tail(x, m); 1107 1108 /* ... maybe discard first sample ... */ 1109 if (pdata->settle_delay_usecs) { 1110 x->delay.value = pdata->settle_delay_usecs; 1111 x->delay.unit = SPI_DELAY_UNIT_USECS; 1112 1113 x++; 1114 x->tx_buf = &packet->read_z1; 1115 x->len = 1; 1116 spi_message_add_tail(x, m); 1117 1118 x++; 1119 x->rx_buf = &packet->tc.z1; 1120 x->len = 2; 1121 spi_message_add_tail(x, m); 1122 } 1123 1124 ts->msg_count++; 1125 m++; 1126 spi_message_init(m); 1127 m->context = ts; 1128 1129 x++; 1130 packet->read_z2 = READ_Z2(vref); 1131 x->tx_buf = &packet->read_z2; 1132 x->len = 1; 1133 spi_message_add_tail(x, m); 1134 1135 x++; 1136 x->rx_buf = &packet->tc.z2; 1137 x->len = 2; 1138 spi_message_add_tail(x, m); 1139 1140 /* ... maybe discard first sample ... */ 1141 if (pdata->settle_delay_usecs) { 1142 x->delay.value = pdata->settle_delay_usecs; 1143 x->delay.unit = SPI_DELAY_UNIT_USECS; 1144 1145 x++; 1146 x->tx_buf = &packet->read_z2; 1147 x->len = 1; 1148 spi_message_add_tail(x, m); 1149 1150 x++; 1151 x->rx_buf = &packet->tc.z2; 1152 x->len = 2; 1153 spi_message_add_tail(x, m); 1154 } 1155 } 1156 1157 /* power down */ 1158 ts->msg_count++; 1159 m++; 1160 spi_message_init(m); 1161 m->context = ts; 1162 1163 if (ts->model == 7845) { 1164 x++; 1165 packet->pwrdown_cmd[0] = PWRDOWN; 1166 packet->pwrdown_cmd[1] = 0; 1167 packet->pwrdown_cmd[2] = 0; 1168 x->tx_buf = &packet->pwrdown_cmd[0]; 1169 x->len = 3; 1170 } else { 1171 x++; 1172 packet->pwrdown = PWRDOWN; 1173 x->tx_buf = &packet->pwrdown; 1174 x->len = 1; 1175 spi_message_add_tail(x, m); 1176 1177 x++; 1178 x->rx_buf = &packet->dummy; 1179 x->len = 2; 1180 } 1181 1182 CS_CHANGE(*x); 1183 spi_message_add_tail(x, m); 1184 } 1185 1186 #ifdef CONFIG_OF 1187 static const struct of_device_id ads7846_dt_ids[] = { 1188 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1189 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1190 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1191 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1192 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1193 { } 1194 }; 1195 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1196 1197 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1198 { 1199 struct ads7846_platform_data *pdata; 1200 struct device_node *node = dev->of_node; 1201 const struct of_device_id *match; 1202 u32 value; 1203 1204 if (!node) { 1205 dev_err(dev, "Device does not have associated DT data\n"); 1206 return ERR_PTR(-EINVAL); 1207 } 1208 1209 match = of_match_device(ads7846_dt_ids, dev); 1210 if (!match) { 1211 dev_err(dev, "Unknown device model\n"); 1212 return ERR_PTR(-EINVAL); 1213 } 1214 1215 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1216 if (!pdata) 1217 return ERR_PTR(-ENOMEM); 1218 1219 pdata->model = (unsigned long)match->data; 1220 1221 of_property_read_u16(node, "ti,vref-delay-usecs", 1222 &pdata->vref_delay_usecs); 1223 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1224 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1225 1226 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1227 1228 of_property_read_u16(node, "ti,settle-delay-usec", 1229 &pdata->settle_delay_usecs); 1230 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1231 &pdata->penirq_recheck_delay_usecs); 1232 1233 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1234 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1235 1236 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1237 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1238 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1239 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1240 1241 /* 1242 * touchscreen-max-pressure gets parsed during 1243 * touchscreen_parse_properties() 1244 */ 1245 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1246 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1247 pdata->pressure_min = (u16) value; 1248 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1249 1250 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1251 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1252 pdata->debounce_max = (u16) value; 1253 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1254 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1255 1256 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1257 &pdata->gpio_pendown_debounce); 1258 1259 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1260 of_property_read_bool(node, "linux,wakeup"); 1261 1262 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1263 1264 return pdata; 1265 } 1266 #else 1267 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1268 { 1269 dev_err(dev, "no platform data defined\n"); 1270 return ERR_PTR(-EINVAL); 1271 } 1272 #endif 1273 1274 static int ads7846_probe(struct spi_device *spi) 1275 { 1276 const struct ads7846_platform_data *pdata; 1277 struct ads7846 *ts; 1278 struct ads7846_packet *packet; 1279 struct input_dev *input_dev; 1280 unsigned long irq_flags; 1281 int err; 1282 1283 if (!spi->irq) { 1284 dev_dbg(&spi->dev, "no IRQ?\n"); 1285 return -EINVAL; 1286 } 1287 1288 /* don't exceed max specified sample rate */ 1289 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1290 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1291 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1292 return -EINVAL; 1293 } 1294 1295 /* 1296 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1297 * that even if the hardware can do that, the SPI controller driver 1298 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1299 */ 1300 spi->bits_per_word = 8; 1301 spi->mode = SPI_MODE_0; 1302 err = spi_setup(spi); 1303 if (err < 0) 1304 return err; 1305 1306 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1307 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1308 input_dev = input_allocate_device(); 1309 if (!ts || !packet || !input_dev) { 1310 err = -ENOMEM; 1311 goto err_free_mem; 1312 } 1313 1314 spi_set_drvdata(spi, ts); 1315 1316 ts->packet = packet; 1317 ts->spi = spi; 1318 ts->input = input_dev; 1319 1320 mutex_init(&ts->lock); 1321 init_waitqueue_head(&ts->wait); 1322 1323 pdata = dev_get_platdata(&spi->dev); 1324 if (!pdata) { 1325 pdata = ads7846_probe_dt(&spi->dev); 1326 if (IS_ERR(pdata)) { 1327 err = PTR_ERR(pdata); 1328 goto err_free_mem; 1329 } 1330 } 1331 1332 ts->model = pdata->model ? : 7846; 1333 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1334 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1335 ts->vref_mv = pdata->vref_mv; 1336 1337 if (pdata->filter != NULL) { 1338 if (pdata->filter_init != NULL) { 1339 err = pdata->filter_init(pdata, &ts->filter_data); 1340 if (err < 0) 1341 goto err_free_mem; 1342 } 1343 ts->filter = pdata->filter; 1344 ts->filter_cleanup = pdata->filter_cleanup; 1345 } else if (pdata->debounce_max) { 1346 ts->debounce_max = pdata->debounce_max; 1347 if (ts->debounce_max < 2) 1348 ts->debounce_max = 2; 1349 ts->debounce_tol = pdata->debounce_tol; 1350 ts->debounce_rep = pdata->debounce_rep; 1351 ts->filter = ads7846_debounce_filter; 1352 ts->filter_data = ts; 1353 } else { 1354 ts->filter = ads7846_no_filter; 1355 } 1356 1357 err = ads7846_setup_pendown(spi, ts, pdata); 1358 if (err) 1359 goto err_cleanup_filter; 1360 1361 if (pdata->penirq_recheck_delay_usecs) 1362 ts->penirq_recheck_delay_usecs = 1363 pdata->penirq_recheck_delay_usecs; 1364 1365 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1366 1367 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1368 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1369 1370 input_dev->name = ts->name; 1371 input_dev->phys = ts->phys; 1372 input_dev->dev.parent = &spi->dev; 1373 1374 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1375 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1376 input_set_abs_params(input_dev, ABS_X, 1377 pdata->x_min ? : 0, 1378 pdata->x_max ? : MAX_12BIT, 1379 0, 0); 1380 input_set_abs_params(input_dev, ABS_Y, 1381 pdata->y_min ? : 0, 1382 pdata->y_max ? : MAX_12BIT, 1383 0, 0); 1384 input_set_abs_params(input_dev, ABS_PRESSURE, 1385 pdata->pressure_min, pdata->pressure_max, 0, 0); 1386 1387 /* 1388 * Parse common framework properties. Must be done here to ensure the 1389 * correct behaviour in case of using the legacy vendor bindings. The 1390 * general binding value overrides the vendor specific one. 1391 */ 1392 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1393 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1394 1395 /* 1396 * Check if legacy ti,swap-xy binding is used instead of 1397 * touchscreen-swapped-x-y 1398 */ 1399 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1400 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1401 ts->core_prop.swap_x_y = true; 1402 } 1403 1404 ads7846_setup_spi_msg(ts, pdata); 1405 1406 ts->reg = regulator_get(&spi->dev, "vcc"); 1407 if (IS_ERR(ts->reg)) { 1408 err = PTR_ERR(ts->reg); 1409 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1410 goto err_free_gpio; 1411 } 1412 1413 err = regulator_enable(ts->reg); 1414 if (err) { 1415 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1416 goto err_put_regulator; 1417 } 1418 1419 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1420 irq_flags |= IRQF_ONESHOT; 1421 1422 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1423 irq_flags, spi->dev.driver->name, ts); 1424 if (err && !pdata->irq_flags) { 1425 dev_info(&spi->dev, 1426 "trying pin change workaround on irq %d\n", spi->irq); 1427 irq_flags |= IRQF_TRIGGER_RISING; 1428 err = request_threaded_irq(spi->irq, 1429 ads7846_hard_irq, ads7846_irq, 1430 irq_flags, spi->dev.driver->name, ts); 1431 } 1432 1433 if (err) { 1434 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1435 goto err_disable_regulator; 1436 } 1437 1438 err = ads784x_hwmon_register(spi, ts); 1439 if (err) 1440 goto err_free_irq; 1441 1442 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1443 1444 /* 1445 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1446 * the touchscreen, in case it's not connected. 1447 */ 1448 if (ts->model == 7845) 1449 ads7845_read12_ser(&spi->dev, PWRDOWN); 1450 else 1451 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1452 1453 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1454 if (err) 1455 goto err_remove_hwmon; 1456 1457 err = input_register_device(input_dev); 1458 if (err) 1459 goto err_remove_attr_group; 1460 1461 device_init_wakeup(&spi->dev, pdata->wakeup); 1462 1463 /* 1464 * If device does not carry platform data we must have allocated it 1465 * when parsing DT data. 1466 */ 1467 if (!dev_get_platdata(&spi->dev)) 1468 devm_kfree(&spi->dev, (void *)pdata); 1469 1470 return 0; 1471 1472 err_remove_attr_group: 1473 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1474 err_remove_hwmon: 1475 ads784x_hwmon_unregister(spi, ts); 1476 err_free_irq: 1477 free_irq(spi->irq, ts); 1478 err_disable_regulator: 1479 regulator_disable(ts->reg); 1480 err_put_regulator: 1481 regulator_put(ts->reg); 1482 err_free_gpio: 1483 if (!ts->get_pendown_state) 1484 gpio_free(ts->gpio_pendown); 1485 err_cleanup_filter: 1486 if (ts->filter_cleanup) 1487 ts->filter_cleanup(ts->filter_data); 1488 err_free_mem: 1489 input_free_device(input_dev); 1490 kfree(packet); 1491 kfree(ts); 1492 return err; 1493 } 1494 1495 static int ads7846_remove(struct spi_device *spi) 1496 { 1497 struct ads7846 *ts = spi_get_drvdata(spi); 1498 1499 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1500 1501 ads7846_disable(ts); 1502 free_irq(ts->spi->irq, ts); 1503 1504 input_unregister_device(ts->input); 1505 1506 ads784x_hwmon_unregister(spi, ts); 1507 1508 regulator_put(ts->reg); 1509 1510 if (!ts->get_pendown_state) { 1511 /* 1512 * If we are not using specialized pendown method we must 1513 * have been relying on gpio we set up ourselves. 1514 */ 1515 gpio_free(ts->gpio_pendown); 1516 } 1517 1518 if (ts->filter_cleanup) 1519 ts->filter_cleanup(ts->filter_data); 1520 1521 kfree(ts->packet); 1522 kfree(ts); 1523 1524 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1525 1526 return 0; 1527 } 1528 1529 static struct spi_driver ads7846_driver = { 1530 .driver = { 1531 .name = "ads7846", 1532 .pm = &ads7846_pm, 1533 .of_match_table = of_match_ptr(ads7846_dt_ids), 1534 }, 1535 .probe = ads7846_probe, 1536 .remove = ads7846_remove, 1537 }; 1538 1539 module_spi_driver(ads7846_driver); 1540 1541 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1542 MODULE_LICENSE("GPL"); 1543 MODULE_ALIAS("spi:ads7846"); 1544