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 = kobj_to_dev(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 *= x; 806 Rt *= ts->x_plate_ohms; 807 Rt /= z1; 808 Rt = (Rt + 2047) >> 12; 809 } else { 810 Rt = 0; 811 } 812 813 /* 814 * Sample found inconsistent by debouncing or pressure is beyond 815 * the maximum. Don't report it to user space, repeat at least 816 * once more the measurement 817 */ 818 if (packet->tc.ignore || Rt > ts->pressure_max) { 819 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 820 packet->tc.ignore, Rt); 821 return; 822 } 823 824 /* 825 * Maybe check the pendown state before reporting. This discards 826 * false readings when the pen is lifted. 827 */ 828 if (ts->penirq_recheck_delay_usecs) { 829 udelay(ts->penirq_recheck_delay_usecs); 830 if (!get_pendown_state(ts)) 831 Rt = 0; 832 } 833 834 /* 835 * NOTE: We can't rely on the pressure to determine the pen down 836 * state, even this controller has a pressure sensor. The pressure 837 * value can fluctuate for quite a while after lifting the pen and 838 * in some cases may not even settle at the expected value. 839 * 840 * The only safe way to check for the pen up condition is in the 841 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 842 */ 843 if (Rt) { 844 struct input_dev *input = ts->input; 845 846 if (!ts->pendown) { 847 input_report_key(input, BTN_TOUCH, 1); 848 ts->pendown = true; 849 dev_vdbg(&ts->spi->dev, "DOWN\n"); 850 } 851 852 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 853 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 854 855 input_sync(input); 856 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 857 } 858 } 859 860 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 861 { 862 struct ads7846 *ts = handle; 863 864 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 865 } 866 867 868 static irqreturn_t ads7846_irq(int irq, void *handle) 869 { 870 struct ads7846 *ts = handle; 871 872 /* Start with a small delay before checking pendown state */ 873 msleep(TS_POLL_DELAY); 874 875 while (!ts->stopped && get_pendown_state(ts)) { 876 877 /* pen is down, continue with the measurement */ 878 ads7846_read_state(ts); 879 880 if (!ts->stopped) 881 ads7846_report_state(ts); 882 883 wait_event_timeout(ts->wait, ts->stopped, 884 msecs_to_jiffies(TS_POLL_PERIOD)); 885 } 886 887 if (ts->pendown && !ts->stopped) 888 ads7846_report_pen_up(ts); 889 890 return IRQ_HANDLED; 891 } 892 893 static int __maybe_unused ads7846_suspend(struct device *dev) 894 { 895 struct ads7846 *ts = dev_get_drvdata(dev); 896 897 mutex_lock(&ts->lock); 898 899 if (!ts->suspended) { 900 901 if (!ts->disabled) 902 __ads7846_disable(ts); 903 904 if (device_may_wakeup(&ts->spi->dev)) 905 enable_irq_wake(ts->spi->irq); 906 907 ts->suspended = true; 908 } 909 910 mutex_unlock(&ts->lock); 911 912 return 0; 913 } 914 915 static int __maybe_unused ads7846_resume(struct device *dev) 916 { 917 struct ads7846 *ts = dev_get_drvdata(dev); 918 919 mutex_lock(&ts->lock); 920 921 if (ts->suspended) { 922 923 ts->suspended = false; 924 925 if (device_may_wakeup(&ts->spi->dev)) 926 disable_irq_wake(ts->spi->irq); 927 928 if (!ts->disabled) 929 __ads7846_enable(ts); 930 } 931 932 mutex_unlock(&ts->lock); 933 934 return 0; 935 } 936 937 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 938 939 static int ads7846_setup_pendown(struct spi_device *spi, 940 struct ads7846 *ts, 941 const struct ads7846_platform_data *pdata) 942 { 943 int err; 944 945 /* 946 * REVISIT when the irq can be triggered active-low, or if for some 947 * reason the touchscreen isn't hooked up, we don't need to access 948 * the pendown state. 949 */ 950 951 if (pdata->get_pendown_state) { 952 ts->get_pendown_state = pdata->get_pendown_state; 953 } else if (gpio_is_valid(pdata->gpio_pendown)) { 954 955 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 956 "ads7846_pendown"); 957 if (err) { 958 dev_err(&spi->dev, 959 "failed to request/setup pendown GPIO%d: %d\n", 960 pdata->gpio_pendown, err); 961 return err; 962 } 963 964 ts->gpio_pendown = pdata->gpio_pendown; 965 966 if (pdata->gpio_pendown_debounce) 967 gpio_set_debounce(pdata->gpio_pendown, 968 pdata->gpio_pendown_debounce); 969 } else { 970 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 971 return -EINVAL; 972 } 973 974 return 0; 975 } 976 977 /* 978 * Set up the transfers to read touchscreen state; this assumes we 979 * use formula #2 for pressure, not #3. 980 */ 981 static void ads7846_setup_spi_msg(struct ads7846 *ts, 982 const struct ads7846_platform_data *pdata) 983 { 984 struct spi_message *m = &ts->msg[0]; 985 struct spi_transfer *x = ts->xfer; 986 struct ads7846_packet *packet = ts->packet; 987 int vref = pdata->keep_vref_on; 988 989 if (ts->model == 7873) { 990 /* 991 * The AD7873 is almost identical to the ADS7846 992 * keep VREF off during differential/ratiometric 993 * conversion modes. 994 */ 995 ts->model = 7846; 996 vref = 0; 997 } 998 999 ts->msg_count = 1; 1000 spi_message_init(m); 1001 m->context = ts; 1002 1003 if (ts->model == 7845) { 1004 packet->read_y_cmd[0] = READ_Y(vref); 1005 packet->read_y_cmd[1] = 0; 1006 packet->read_y_cmd[2] = 0; 1007 x->tx_buf = &packet->read_y_cmd[0]; 1008 x->rx_buf = &packet->tc.y_buf[0]; 1009 x->len = 3; 1010 spi_message_add_tail(x, m); 1011 } else { 1012 /* y- still on; turn on only y+ (and ADC) */ 1013 packet->read_y = READ_Y(vref); 1014 x->tx_buf = &packet->read_y; 1015 x->len = 1; 1016 spi_message_add_tail(x, m); 1017 1018 x++; 1019 x->rx_buf = &packet->tc.y; 1020 x->len = 2; 1021 spi_message_add_tail(x, m); 1022 } 1023 1024 /* 1025 * The first sample after switching drivers can be low quality; 1026 * optionally discard it, using a second one after the signals 1027 * have had enough time to stabilize. 1028 */ 1029 if (pdata->settle_delay_usecs) { 1030 x->delay.value = pdata->settle_delay_usecs; 1031 x->delay.unit = SPI_DELAY_UNIT_USECS; 1032 1033 x++; 1034 x->tx_buf = &packet->read_y; 1035 x->len = 1; 1036 spi_message_add_tail(x, m); 1037 1038 x++; 1039 x->rx_buf = &packet->tc.y; 1040 x->len = 2; 1041 spi_message_add_tail(x, m); 1042 } 1043 1044 ts->msg_count++; 1045 m++; 1046 spi_message_init(m); 1047 m->context = ts; 1048 1049 if (ts->model == 7845) { 1050 x++; 1051 packet->read_x_cmd[0] = READ_X(vref); 1052 packet->read_x_cmd[1] = 0; 1053 packet->read_x_cmd[2] = 0; 1054 x->tx_buf = &packet->read_x_cmd[0]; 1055 x->rx_buf = &packet->tc.x_buf[0]; 1056 x->len = 3; 1057 spi_message_add_tail(x, m); 1058 } else { 1059 /* turn y- off, x+ on, then leave in lowpower */ 1060 x++; 1061 packet->read_x = READ_X(vref); 1062 x->tx_buf = &packet->read_x; 1063 x->len = 1; 1064 spi_message_add_tail(x, m); 1065 1066 x++; 1067 x->rx_buf = &packet->tc.x; 1068 x->len = 2; 1069 spi_message_add_tail(x, m); 1070 } 1071 1072 /* ... maybe discard first sample ... */ 1073 if (pdata->settle_delay_usecs) { 1074 x->delay.value = pdata->settle_delay_usecs; 1075 x->delay.unit = SPI_DELAY_UNIT_USECS; 1076 1077 x++; 1078 x->tx_buf = &packet->read_x; 1079 x->len = 1; 1080 spi_message_add_tail(x, m); 1081 1082 x++; 1083 x->rx_buf = &packet->tc.x; 1084 x->len = 2; 1085 spi_message_add_tail(x, m); 1086 } 1087 1088 /* turn y+ off, x- on; we'll use formula #2 */ 1089 if (ts->model == 7846) { 1090 ts->msg_count++; 1091 m++; 1092 spi_message_init(m); 1093 m->context = ts; 1094 1095 x++; 1096 packet->read_z1 = READ_Z1(vref); 1097 x->tx_buf = &packet->read_z1; 1098 x->len = 1; 1099 spi_message_add_tail(x, m); 1100 1101 x++; 1102 x->rx_buf = &packet->tc.z1; 1103 x->len = 2; 1104 spi_message_add_tail(x, m); 1105 1106 /* ... maybe discard first sample ... */ 1107 if (pdata->settle_delay_usecs) { 1108 x->delay.value = pdata->settle_delay_usecs; 1109 x->delay.unit = SPI_DELAY_UNIT_USECS; 1110 1111 x++; 1112 x->tx_buf = &packet->read_z1; 1113 x->len = 1; 1114 spi_message_add_tail(x, m); 1115 1116 x++; 1117 x->rx_buf = &packet->tc.z1; 1118 x->len = 2; 1119 spi_message_add_tail(x, m); 1120 } 1121 1122 ts->msg_count++; 1123 m++; 1124 spi_message_init(m); 1125 m->context = ts; 1126 1127 x++; 1128 packet->read_z2 = READ_Z2(vref); 1129 x->tx_buf = &packet->read_z2; 1130 x->len = 1; 1131 spi_message_add_tail(x, m); 1132 1133 x++; 1134 x->rx_buf = &packet->tc.z2; 1135 x->len = 2; 1136 spi_message_add_tail(x, m); 1137 1138 /* ... maybe discard first sample ... */ 1139 if (pdata->settle_delay_usecs) { 1140 x->delay.value = pdata->settle_delay_usecs; 1141 x->delay.unit = SPI_DELAY_UNIT_USECS; 1142 1143 x++; 1144 x->tx_buf = &packet->read_z2; 1145 x->len = 1; 1146 spi_message_add_tail(x, m); 1147 1148 x++; 1149 x->rx_buf = &packet->tc.z2; 1150 x->len = 2; 1151 spi_message_add_tail(x, m); 1152 } 1153 } 1154 1155 /* power down */ 1156 ts->msg_count++; 1157 m++; 1158 spi_message_init(m); 1159 m->context = ts; 1160 1161 if (ts->model == 7845) { 1162 x++; 1163 packet->pwrdown_cmd[0] = PWRDOWN; 1164 packet->pwrdown_cmd[1] = 0; 1165 packet->pwrdown_cmd[2] = 0; 1166 x->tx_buf = &packet->pwrdown_cmd[0]; 1167 x->len = 3; 1168 } else { 1169 x++; 1170 packet->pwrdown = PWRDOWN; 1171 x->tx_buf = &packet->pwrdown; 1172 x->len = 1; 1173 spi_message_add_tail(x, m); 1174 1175 x++; 1176 x->rx_buf = &packet->dummy; 1177 x->len = 2; 1178 } 1179 1180 CS_CHANGE(*x); 1181 spi_message_add_tail(x, m); 1182 } 1183 1184 #ifdef CONFIG_OF 1185 static const struct of_device_id ads7846_dt_ids[] = { 1186 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1187 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1188 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1189 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1190 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1191 { } 1192 }; 1193 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1194 1195 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1196 { 1197 struct ads7846_platform_data *pdata; 1198 struct device_node *node = dev->of_node; 1199 const struct of_device_id *match; 1200 u32 value; 1201 1202 if (!node) { 1203 dev_err(dev, "Device does not have associated DT data\n"); 1204 return ERR_PTR(-EINVAL); 1205 } 1206 1207 match = of_match_device(ads7846_dt_ids, dev); 1208 if (!match) { 1209 dev_err(dev, "Unknown device model\n"); 1210 return ERR_PTR(-EINVAL); 1211 } 1212 1213 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1214 if (!pdata) 1215 return ERR_PTR(-ENOMEM); 1216 1217 pdata->model = (unsigned long)match->data; 1218 1219 of_property_read_u16(node, "ti,vref-delay-usecs", 1220 &pdata->vref_delay_usecs); 1221 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1222 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1223 1224 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1225 1226 of_property_read_u16(node, "ti,settle-delay-usec", 1227 &pdata->settle_delay_usecs); 1228 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1229 &pdata->penirq_recheck_delay_usecs); 1230 1231 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1232 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1233 1234 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1235 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1236 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1237 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1238 1239 /* 1240 * touchscreen-max-pressure gets parsed during 1241 * touchscreen_parse_properties() 1242 */ 1243 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1244 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1245 pdata->pressure_min = (u16) value; 1246 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1247 1248 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1249 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1250 pdata->debounce_max = (u16) value; 1251 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1252 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1253 1254 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1255 &pdata->gpio_pendown_debounce); 1256 1257 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1258 of_property_read_bool(node, "linux,wakeup"); 1259 1260 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1261 1262 return pdata; 1263 } 1264 #else 1265 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1266 { 1267 dev_err(dev, "no platform data defined\n"); 1268 return ERR_PTR(-EINVAL); 1269 } 1270 #endif 1271 1272 static int ads7846_probe(struct spi_device *spi) 1273 { 1274 const struct ads7846_platform_data *pdata; 1275 struct ads7846 *ts; 1276 struct ads7846_packet *packet; 1277 struct input_dev *input_dev; 1278 unsigned long irq_flags; 1279 int err; 1280 1281 if (!spi->irq) { 1282 dev_dbg(&spi->dev, "no IRQ?\n"); 1283 return -EINVAL; 1284 } 1285 1286 /* don't exceed max specified sample rate */ 1287 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1288 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1289 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1290 return -EINVAL; 1291 } 1292 1293 /* 1294 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1295 * that even if the hardware can do that, the SPI controller driver 1296 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1297 */ 1298 spi->bits_per_word = 8; 1299 spi->mode = SPI_MODE_0; 1300 err = spi_setup(spi); 1301 if (err < 0) 1302 return err; 1303 1304 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1305 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1306 input_dev = input_allocate_device(); 1307 if (!ts || !packet || !input_dev) { 1308 err = -ENOMEM; 1309 goto err_free_mem; 1310 } 1311 1312 spi_set_drvdata(spi, ts); 1313 1314 ts->packet = packet; 1315 ts->spi = spi; 1316 ts->input = input_dev; 1317 1318 mutex_init(&ts->lock); 1319 init_waitqueue_head(&ts->wait); 1320 1321 pdata = dev_get_platdata(&spi->dev); 1322 if (!pdata) { 1323 pdata = ads7846_probe_dt(&spi->dev); 1324 if (IS_ERR(pdata)) { 1325 err = PTR_ERR(pdata); 1326 goto err_free_mem; 1327 } 1328 } 1329 1330 ts->model = pdata->model ? : 7846; 1331 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1332 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1333 ts->vref_mv = pdata->vref_mv; 1334 1335 if (pdata->filter != NULL) { 1336 if (pdata->filter_init != NULL) { 1337 err = pdata->filter_init(pdata, &ts->filter_data); 1338 if (err < 0) 1339 goto err_free_mem; 1340 } 1341 ts->filter = pdata->filter; 1342 ts->filter_cleanup = pdata->filter_cleanup; 1343 } else if (pdata->debounce_max) { 1344 ts->debounce_max = pdata->debounce_max; 1345 if (ts->debounce_max < 2) 1346 ts->debounce_max = 2; 1347 ts->debounce_tol = pdata->debounce_tol; 1348 ts->debounce_rep = pdata->debounce_rep; 1349 ts->filter = ads7846_debounce_filter; 1350 ts->filter_data = ts; 1351 } else { 1352 ts->filter = ads7846_no_filter; 1353 } 1354 1355 err = ads7846_setup_pendown(spi, ts, pdata); 1356 if (err) 1357 goto err_cleanup_filter; 1358 1359 if (pdata->penirq_recheck_delay_usecs) 1360 ts->penirq_recheck_delay_usecs = 1361 pdata->penirq_recheck_delay_usecs; 1362 1363 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1364 1365 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1366 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1367 1368 input_dev->name = ts->name; 1369 input_dev->phys = ts->phys; 1370 input_dev->dev.parent = &spi->dev; 1371 1372 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1373 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1374 input_set_abs_params(input_dev, ABS_X, 1375 pdata->x_min ? : 0, 1376 pdata->x_max ? : MAX_12BIT, 1377 0, 0); 1378 input_set_abs_params(input_dev, ABS_Y, 1379 pdata->y_min ? : 0, 1380 pdata->y_max ? : MAX_12BIT, 1381 0, 0); 1382 input_set_abs_params(input_dev, ABS_PRESSURE, 1383 pdata->pressure_min, pdata->pressure_max, 0, 0); 1384 1385 /* 1386 * Parse common framework properties. Must be done here to ensure the 1387 * correct behaviour in case of using the legacy vendor bindings. The 1388 * general binding value overrides the vendor specific one. 1389 */ 1390 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1391 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1392 1393 /* 1394 * Check if legacy ti,swap-xy binding is used instead of 1395 * touchscreen-swapped-x-y 1396 */ 1397 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1398 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1399 ts->core_prop.swap_x_y = true; 1400 } 1401 1402 ads7846_setup_spi_msg(ts, pdata); 1403 1404 ts->reg = regulator_get(&spi->dev, "vcc"); 1405 if (IS_ERR(ts->reg)) { 1406 err = PTR_ERR(ts->reg); 1407 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1408 goto err_free_gpio; 1409 } 1410 1411 err = regulator_enable(ts->reg); 1412 if (err) { 1413 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1414 goto err_put_regulator; 1415 } 1416 1417 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1418 irq_flags |= IRQF_ONESHOT; 1419 1420 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1421 irq_flags, spi->dev.driver->name, ts); 1422 if (err && !pdata->irq_flags) { 1423 dev_info(&spi->dev, 1424 "trying pin change workaround on irq %d\n", spi->irq); 1425 irq_flags |= IRQF_TRIGGER_RISING; 1426 err = request_threaded_irq(spi->irq, 1427 ads7846_hard_irq, ads7846_irq, 1428 irq_flags, spi->dev.driver->name, ts); 1429 } 1430 1431 if (err) { 1432 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1433 goto err_disable_regulator; 1434 } 1435 1436 err = ads784x_hwmon_register(spi, ts); 1437 if (err) 1438 goto err_free_irq; 1439 1440 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1441 1442 /* 1443 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1444 * the touchscreen, in case it's not connected. 1445 */ 1446 if (ts->model == 7845) 1447 ads7845_read12_ser(&spi->dev, PWRDOWN); 1448 else 1449 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1450 1451 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1452 if (err) 1453 goto err_remove_hwmon; 1454 1455 err = input_register_device(input_dev); 1456 if (err) 1457 goto err_remove_attr_group; 1458 1459 device_init_wakeup(&spi->dev, pdata->wakeup); 1460 1461 /* 1462 * If device does not carry platform data we must have allocated it 1463 * when parsing DT data. 1464 */ 1465 if (!dev_get_platdata(&spi->dev)) 1466 devm_kfree(&spi->dev, (void *)pdata); 1467 1468 return 0; 1469 1470 err_remove_attr_group: 1471 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1472 err_remove_hwmon: 1473 ads784x_hwmon_unregister(spi, ts); 1474 err_free_irq: 1475 free_irq(spi->irq, ts); 1476 err_disable_regulator: 1477 regulator_disable(ts->reg); 1478 err_put_regulator: 1479 regulator_put(ts->reg); 1480 err_free_gpio: 1481 if (!ts->get_pendown_state) 1482 gpio_free(ts->gpio_pendown); 1483 err_cleanup_filter: 1484 if (ts->filter_cleanup) 1485 ts->filter_cleanup(ts->filter_data); 1486 err_free_mem: 1487 input_free_device(input_dev); 1488 kfree(packet); 1489 kfree(ts); 1490 return err; 1491 } 1492 1493 static int ads7846_remove(struct spi_device *spi) 1494 { 1495 struct ads7846 *ts = spi_get_drvdata(spi); 1496 1497 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1498 1499 ads7846_disable(ts); 1500 free_irq(ts->spi->irq, ts); 1501 1502 input_unregister_device(ts->input); 1503 1504 ads784x_hwmon_unregister(spi, ts); 1505 1506 regulator_put(ts->reg); 1507 1508 if (!ts->get_pendown_state) { 1509 /* 1510 * If we are not using specialized pendown method we must 1511 * have been relying on gpio we set up ourselves. 1512 */ 1513 gpio_free(ts->gpio_pendown); 1514 } 1515 1516 if (ts->filter_cleanup) 1517 ts->filter_cleanup(ts->filter_data); 1518 1519 kfree(ts->packet); 1520 kfree(ts); 1521 1522 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1523 1524 return 0; 1525 } 1526 1527 static struct spi_driver ads7846_driver = { 1528 .driver = { 1529 .name = "ads7846", 1530 .pm = &ads7846_pm, 1531 .of_match_table = of_match_ptr(ads7846_dt_ids), 1532 }, 1533 .probe = ads7846_probe, 1534 .remove = ads7846_remove, 1535 }; 1536 1537 module_spi_driver(ads7846_driver); 1538 1539 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1540 MODULE_LICENSE("GPL"); 1541 MODULE_ALIAS("spi:ads7846"); 1542