1 /* 2 * ADS7846 based touchscreen and sensor driver 3 * 4 * Copyright (c) 2005 David Brownell 5 * Copyright (c) 2006 Nokia Corporation 6 * Various changes: Imre Deak <imre.deak@nokia.com> 7 * 8 * Using code from: 9 * - corgi_ts.c 10 * Copyright (C) 2004-2005 Richard Purdie 11 * - omap_ts.[hc], ads7846.h, ts_osk.c 12 * Copyright (C) 2002 MontaVista Software 13 * Copyright (C) 2004 Texas Instruments 14 * Copyright (C) 2005 Dirk Behme 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License version 2 as 18 * published by the Free Software Foundation. 19 */ 20 #include <linux/types.h> 21 #include <linux/hwmon.h> 22 #include <linux/err.h> 23 #include <linux/sched.h> 24 #include <linux/delay.h> 25 #include <linux/input.h> 26 #include <linux/interrupt.h> 27 #include <linux/slab.h> 28 #include <linux/pm.h> 29 #include <linux/of.h> 30 #include <linux/of_gpio.h> 31 #include <linux/of_device.h> 32 #include <linux/gpio.h> 33 #include <linux/spi/spi.h> 34 #include <linux/spi/ads7846.h> 35 #include <linux/regulator/consumer.h> 36 #include <linux/module.h> 37 #include <asm/irq.h> 38 39 /* 40 * This code has been heavily tested on a Nokia 770, and lightly 41 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 42 * TSC2046 is just newer ads7846 silicon. 43 * Support for ads7843 tested on Atmel at91sam926x-EK. 44 * Support for ads7845 has only been stubbed in. 45 * Support for Analog Devices AD7873 and AD7843 tested. 46 * 47 * IRQ handling needs a workaround because of a shortcoming in handling 48 * edge triggered IRQs on some platforms like the OMAP1/2. These 49 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 50 * have to maintain our own SW IRQ disabled status. This should be 51 * removed as soon as the affected platform's IRQ handling is fixed. 52 * 53 * App note sbaa036 talks in more detail about accurate sampling... 54 * that ought to help in situations like LCDs inducing noise (which 55 * can also be helped by using synch signals) and more generally. 56 * This driver tries to utilize the measures described in the app 57 * note. The strength of filtering can be set in the board-* specific 58 * files. 59 */ 60 61 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 62 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 63 64 /* this driver doesn't aim at the peak continuous sample rate */ 65 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 66 67 struct ts_event { 68 /* 69 * For portability, we can't read 12 bit values using SPI (which 70 * would make the controller deliver them as native byte order u16 71 * with msbs zeroed). Instead, we read them as two 8-bit values, 72 * *** WHICH NEED BYTESWAPPING *** and range adjustment. 73 */ 74 u16 x; 75 u16 y; 76 u16 z1, z2; 77 bool ignore; 78 u8 x_buf[3]; 79 u8 y_buf[3]; 80 }; 81 82 /* 83 * We allocate this separately to avoid cache line sharing issues when 84 * driver is used with DMA-based SPI controllers (like atmel_spi) on 85 * systems where main memory is not DMA-coherent (most non-x86 boards). 86 */ 87 struct ads7846_packet { 88 u8 read_x, read_y, read_z1, read_z2, pwrdown; 89 u16 dummy; /* for the pwrdown read */ 90 struct ts_event tc; 91 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ 92 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; 93 }; 94 95 struct ads7846 { 96 struct input_dev *input; 97 char phys[32]; 98 char name[32]; 99 100 struct spi_device *spi; 101 struct regulator *reg; 102 103 #if IS_ENABLED(CONFIG_HWMON) 104 struct device *hwmon; 105 #endif 106 107 u16 model; 108 u16 vref_mv; 109 u16 vref_delay_usecs; 110 u16 x_plate_ohms; 111 u16 pressure_max; 112 113 bool swap_xy; 114 bool use_internal; 115 116 struct ads7846_packet *packet; 117 118 struct spi_transfer xfer[18]; 119 struct spi_message msg[5]; 120 int msg_count; 121 wait_queue_head_t wait; 122 123 bool pendown; 124 125 int read_cnt; 126 int read_rep; 127 int last_read; 128 129 u16 debounce_max; 130 u16 debounce_tol; 131 u16 debounce_rep; 132 133 u16 penirq_recheck_delay_usecs; 134 135 struct mutex lock; 136 bool stopped; /* P: lock */ 137 bool disabled; /* P: lock */ 138 bool suspended; /* P: lock */ 139 140 int (*filter)(void *data, int data_idx, int *val); 141 void *filter_data; 142 void (*filter_cleanup)(void *data); 143 int (*get_pendown_state)(void); 144 int gpio_pendown; 145 146 void (*wait_for_sync)(void); 147 }; 148 149 /* leave chip selected when we're done, for quicker re-select? */ 150 #if 0 151 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 152 #else 153 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 154 #endif 155 156 /*--------------------------------------------------------------------------*/ 157 158 /* The ADS7846 has touchscreen and other sensors. 159 * Earlier ads784x chips are somewhat compatible. 160 */ 161 #define ADS_START (1 << 7) 162 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 163 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 164 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 165 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 166 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 167 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 168 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 169 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 170 #define ADS_8_BIT (1 << 3) 171 #define ADS_12_BIT (0 << 3) 172 #define ADS_SER (1 << 2) /* non-differential */ 173 #define ADS_DFR (0 << 2) /* differential */ 174 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 175 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 176 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 177 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 178 179 #define MAX_12BIT ((1<<12)-1) 180 181 /* leave ADC powered up (disables penirq) between differential samples */ 182 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 183 | ADS_12_BIT | ADS_DFR | \ 184 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 185 186 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 187 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 188 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 189 190 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 191 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 192 193 /* single-ended samples need to first power up reference voltage; 194 * we leave both ADC and VREF powered 195 */ 196 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 197 | ADS_12_BIT | ADS_SER) 198 199 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 200 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 201 202 /* Must be called with ts->lock held */ 203 static void ads7846_stop(struct ads7846 *ts) 204 { 205 if (!ts->disabled && !ts->suspended) { 206 /* Signal IRQ thread to stop polling and disable the handler. */ 207 ts->stopped = true; 208 mb(); 209 wake_up(&ts->wait); 210 disable_irq(ts->spi->irq); 211 } 212 } 213 214 /* Must be called with ts->lock held */ 215 static void ads7846_restart(struct ads7846 *ts) 216 { 217 if (!ts->disabled && !ts->suspended) { 218 /* Tell IRQ thread that it may poll the device. */ 219 ts->stopped = false; 220 mb(); 221 enable_irq(ts->spi->irq); 222 } 223 } 224 225 /* Must be called with ts->lock held */ 226 static void __ads7846_disable(struct ads7846 *ts) 227 { 228 ads7846_stop(ts); 229 regulator_disable(ts->reg); 230 231 /* 232 * We know the chip's in low power mode since we always 233 * leave it that way after every request 234 */ 235 } 236 237 /* Must be called with ts->lock held */ 238 static void __ads7846_enable(struct ads7846 *ts) 239 { 240 int error; 241 242 error = regulator_enable(ts->reg); 243 if (error != 0) 244 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 245 246 ads7846_restart(ts); 247 } 248 249 static void ads7846_disable(struct ads7846 *ts) 250 { 251 mutex_lock(&ts->lock); 252 253 if (!ts->disabled) { 254 255 if (!ts->suspended) 256 __ads7846_disable(ts); 257 258 ts->disabled = true; 259 } 260 261 mutex_unlock(&ts->lock); 262 } 263 264 static void ads7846_enable(struct ads7846 *ts) 265 { 266 mutex_lock(&ts->lock); 267 268 if (ts->disabled) { 269 270 ts->disabled = false; 271 272 if (!ts->suspended) 273 __ads7846_enable(ts); 274 } 275 276 mutex_unlock(&ts->lock); 277 } 278 279 /*--------------------------------------------------------------------------*/ 280 281 /* 282 * Non-touchscreen sensors only use single-ended conversions. 283 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 284 * ads7846 lets that pin be unconnected, to use internal vREF. 285 */ 286 287 struct ser_req { 288 u8 ref_on; 289 u8 command; 290 u8 ref_off; 291 u16 scratch; 292 struct spi_message msg; 293 struct spi_transfer xfer[6]; 294 /* 295 * DMA (thus cache coherency maintenance) requires the 296 * transfer buffers to live in their own cache lines. 297 */ 298 __be16 sample ____cacheline_aligned; 299 }; 300 301 struct ads7845_ser_req { 302 u8 command[3]; 303 struct spi_message msg; 304 struct spi_transfer xfer[2]; 305 /* 306 * DMA (thus cache coherency maintenance) requires the 307 * transfer buffers to live in their own cache lines. 308 */ 309 u8 sample[3] ____cacheline_aligned; 310 }; 311 312 static int ads7846_read12_ser(struct device *dev, unsigned command) 313 { 314 struct spi_device *spi = to_spi_device(dev); 315 struct ads7846 *ts = dev_get_drvdata(dev); 316 struct ser_req *req; 317 int status; 318 319 req = kzalloc(sizeof *req, GFP_KERNEL); 320 if (!req) 321 return -ENOMEM; 322 323 spi_message_init(&req->msg); 324 325 /* maybe turn on internal vREF, and let it settle */ 326 if (ts->use_internal) { 327 req->ref_on = REF_ON; 328 req->xfer[0].tx_buf = &req->ref_on; 329 req->xfer[0].len = 1; 330 spi_message_add_tail(&req->xfer[0], &req->msg); 331 332 req->xfer[1].rx_buf = &req->scratch; 333 req->xfer[1].len = 2; 334 335 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 336 req->xfer[1].delay_usecs = ts->vref_delay_usecs; 337 spi_message_add_tail(&req->xfer[1], &req->msg); 338 339 /* Enable reference voltage */ 340 command |= ADS_PD10_REF_ON; 341 } 342 343 /* Enable ADC in every case */ 344 command |= ADS_PD10_ADC_ON; 345 346 /* take sample */ 347 req->command = (u8) command; 348 req->xfer[2].tx_buf = &req->command; 349 req->xfer[2].len = 1; 350 spi_message_add_tail(&req->xfer[2], &req->msg); 351 352 req->xfer[3].rx_buf = &req->sample; 353 req->xfer[3].len = 2; 354 spi_message_add_tail(&req->xfer[3], &req->msg); 355 356 /* REVISIT: take a few more samples, and compare ... */ 357 358 /* converter in low power mode & enable PENIRQ */ 359 req->ref_off = PWRDOWN; 360 req->xfer[4].tx_buf = &req->ref_off; 361 req->xfer[4].len = 1; 362 spi_message_add_tail(&req->xfer[4], &req->msg); 363 364 req->xfer[5].rx_buf = &req->scratch; 365 req->xfer[5].len = 2; 366 CS_CHANGE(req->xfer[5]); 367 spi_message_add_tail(&req->xfer[5], &req->msg); 368 369 mutex_lock(&ts->lock); 370 ads7846_stop(ts); 371 status = spi_sync(spi, &req->msg); 372 ads7846_restart(ts); 373 mutex_unlock(&ts->lock); 374 375 if (status == 0) { 376 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 377 status = be16_to_cpu(req->sample); 378 status = status >> 3; 379 status &= 0x0fff; 380 } 381 382 kfree(req); 383 return status; 384 } 385 386 static int ads7845_read12_ser(struct device *dev, unsigned command) 387 { 388 struct spi_device *spi = to_spi_device(dev); 389 struct ads7846 *ts = dev_get_drvdata(dev); 390 struct ads7845_ser_req *req; 391 int status; 392 393 req = kzalloc(sizeof *req, GFP_KERNEL); 394 if (!req) 395 return -ENOMEM; 396 397 spi_message_init(&req->msg); 398 399 req->command[0] = (u8) command; 400 req->xfer[0].tx_buf = req->command; 401 req->xfer[0].rx_buf = req->sample; 402 req->xfer[0].len = 3; 403 spi_message_add_tail(&req->xfer[0], &req->msg); 404 405 mutex_lock(&ts->lock); 406 ads7846_stop(ts); 407 status = spi_sync(spi, &req->msg); 408 ads7846_restart(ts); 409 mutex_unlock(&ts->lock); 410 411 if (status == 0) { 412 /* BE12 value, then padding */ 413 status = be16_to_cpu(*((u16 *)&req->sample[1])); 414 status = status >> 3; 415 status &= 0x0fff; 416 } 417 418 kfree(req); 419 return status; 420 } 421 422 #if IS_ENABLED(CONFIG_HWMON) 423 424 #define SHOW(name, var, adjust) static ssize_t \ 425 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 426 { \ 427 struct ads7846 *ts = dev_get_drvdata(dev); \ 428 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 429 READ_12BIT_SER(var)); \ 430 if (v < 0) \ 431 return v; \ 432 return sprintf(buf, "%u\n", adjust(ts, v)); \ 433 } \ 434 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 435 436 437 /* Sysfs conventions report temperatures in millidegrees Celsius. 438 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 439 * accuracy scheme without calibration data. For now we won't try either; 440 * userspace sees raw sensor values, and must scale/calibrate appropriately. 441 */ 442 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 443 { 444 return v; 445 } 446 447 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 448 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 449 450 451 /* sysfs conventions report voltages in millivolts. We can convert voltages 452 * if we know vREF. userspace may need to scale vAUX to match the board's 453 * external resistors; we assume that vBATT only uses the internal ones. 454 */ 455 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 456 { 457 unsigned retval = v; 458 459 /* external resistors may scale vAUX into 0..vREF */ 460 retval *= ts->vref_mv; 461 retval = retval >> 12; 462 463 return retval; 464 } 465 466 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 467 { 468 unsigned retval = vaux_adjust(ts, v); 469 470 /* ads7846 has a resistor ladder to scale this signal down */ 471 if (ts->model == 7846) 472 retval *= 4; 473 474 return retval; 475 } 476 477 SHOW(in0_input, vaux, vaux_adjust) 478 SHOW(in1_input, vbatt, vbatt_adjust) 479 480 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 481 int index) 482 { 483 struct device *dev = container_of(kobj, struct device, kobj); 484 struct ads7846 *ts = dev_get_drvdata(dev); 485 486 if (ts->model == 7843 && index < 2) /* in0, in1 */ 487 return 0; 488 if (ts->model == 7845 && index != 2) /* in0 */ 489 return 0; 490 491 return attr->mode; 492 } 493 494 static struct attribute *ads7846_attributes[] = { 495 &dev_attr_temp0.attr, /* 0 */ 496 &dev_attr_temp1.attr, /* 1 */ 497 &dev_attr_in0_input.attr, /* 2 */ 498 &dev_attr_in1_input.attr, /* 3 */ 499 NULL, 500 }; 501 502 static struct attribute_group ads7846_attr_group = { 503 .attrs = ads7846_attributes, 504 .is_visible = ads7846_is_visible, 505 }; 506 __ATTRIBUTE_GROUPS(ads7846_attr); 507 508 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 509 { 510 /* hwmon sensors need a reference voltage */ 511 switch (ts->model) { 512 case 7846: 513 if (!ts->vref_mv) { 514 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 515 ts->vref_mv = 2500; 516 ts->use_internal = true; 517 } 518 break; 519 case 7845: 520 case 7843: 521 if (!ts->vref_mv) { 522 dev_warn(&spi->dev, 523 "external vREF for ADS%d not specified\n", 524 ts->model); 525 return 0; 526 } 527 break; 528 } 529 530 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 531 ts, ads7846_attr_groups); 532 533 return PTR_ERR_OR_ZERO(ts->hwmon); 534 } 535 536 static void ads784x_hwmon_unregister(struct spi_device *spi, 537 struct ads7846 *ts) 538 { 539 if (ts->hwmon) 540 hwmon_device_unregister(ts->hwmon); 541 } 542 543 #else 544 static inline int ads784x_hwmon_register(struct spi_device *spi, 545 struct ads7846 *ts) 546 { 547 return 0; 548 } 549 550 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 551 struct ads7846 *ts) 552 { 553 } 554 #endif 555 556 static ssize_t ads7846_pen_down_show(struct device *dev, 557 struct device_attribute *attr, char *buf) 558 { 559 struct ads7846 *ts = dev_get_drvdata(dev); 560 561 return sprintf(buf, "%u\n", ts->pendown); 562 } 563 564 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 565 566 static ssize_t ads7846_disable_show(struct device *dev, 567 struct device_attribute *attr, char *buf) 568 { 569 struct ads7846 *ts = dev_get_drvdata(dev); 570 571 return sprintf(buf, "%u\n", ts->disabled); 572 } 573 574 static ssize_t ads7846_disable_store(struct device *dev, 575 struct device_attribute *attr, 576 const char *buf, size_t count) 577 { 578 struct ads7846 *ts = dev_get_drvdata(dev); 579 unsigned int i; 580 int err; 581 582 err = kstrtouint(buf, 10, &i); 583 if (err) 584 return err; 585 586 if (i) 587 ads7846_disable(ts); 588 else 589 ads7846_enable(ts); 590 591 return count; 592 } 593 594 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 595 596 static struct attribute *ads784x_attributes[] = { 597 &dev_attr_pen_down.attr, 598 &dev_attr_disable.attr, 599 NULL, 600 }; 601 602 static struct attribute_group ads784x_attr_group = { 603 .attrs = ads784x_attributes, 604 }; 605 606 /*--------------------------------------------------------------------------*/ 607 608 static int get_pendown_state(struct ads7846 *ts) 609 { 610 if (ts->get_pendown_state) 611 return ts->get_pendown_state(); 612 613 return !gpio_get_value(ts->gpio_pendown); 614 } 615 616 static void null_wait_for_sync(void) 617 { 618 } 619 620 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 621 { 622 struct ads7846 *ts = ads; 623 624 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 625 /* Start over collecting consistent readings. */ 626 ts->read_rep = 0; 627 /* 628 * Repeat it, if this was the first read or the read 629 * wasn't consistent enough. 630 */ 631 if (ts->read_cnt < ts->debounce_max) { 632 ts->last_read = *val; 633 ts->read_cnt++; 634 return ADS7846_FILTER_REPEAT; 635 } else { 636 /* 637 * Maximum number of debouncing reached and still 638 * not enough number of consistent readings. Abort 639 * the whole sample, repeat it in the next sampling 640 * period. 641 */ 642 ts->read_cnt = 0; 643 return ADS7846_FILTER_IGNORE; 644 } 645 } else { 646 if (++ts->read_rep > ts->debounce_rep) { 647 /* 648 * Got a good reading for this coordinate, 649 * go for the next one. 650 */ 651 ts->read_cnt = 0; 652 ts->read_rep = 0; 653 return ADS7846_FILTER_OK; 654 } else { 655 /* Read more values that are consistent. */ 656 ts->read_cnt++; 657 return ADS7846_FILTER_REPEAT; 658 } 659 } 660 } 661 662 static int ads7846_no_filter(void *ads, int data_idx, int *val) 663 { 664 return ADS7846_FILTER_OK; 665 } 666 667 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 668 { 669 int value; 670 struct spi_transfer *t = 671 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 672 673 if (ts->model == 7845) { 674 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); 675 } else { 676 /* 677 * adjust: on-wire is a must-ignore bit, a BE12 value, then 678 * padding; built from two 8 bit values written msb-first. 679 */ 680 value = be16_to_cpup((__be16 *)t->rx_buf); 681 } 682 683 /* enforce ADC output is 12 bits width */ 684 return (value >> 3) & 0xfff; 685 } 686 687 static void ads7846_update_value(struct spi_message *m, int val) 688 { 689 struct spi_transfer *t = 690 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 691 692 *(u16 *)t->rx_buf = val; 693 } 694 695 static void ads7846_read_state(struct ads7846 *ts) 696 { 697 struct ads7846_packet *packet = ts->packet; 698 struct spi_message *m; 699 int msg_idx = 0; 700 int val; 701 int action; 702 int error; 703 704 while (msg_idx < ts->msg_count) { 705 706 ts->wait_for_sync(); 707 708 m = &ts->msg[msg_idx]; 709 error = spi_sync(ts->spi, m); 710 if (error) { 711 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 712 packet->tc.ignore = true; 713 return; 714 } 715 716 /* 717 * Last message is power down request, no need to convert 718 * or filter the value. 719 */ 720 if (msg_idx < ts->msg_count - 1) { 721 722 val = ads7846_get_value(ts, m); 723 724 action = ts->filter(ts->filter_data, msg_idx, &val); 725 switch (action) { 726 case ADS7846_FILTER_REPEAT: 727 continue; 728 729 case ADS7846_FILTER_IGNORE: 730 packet->tc.ignore = true; 731 msg_idx = ts->msg_count - 1; 732 continue; 733 734 case ADS7846_FILTER_OK: 735 ads7846_update_value(m, val); 736 packet->tc.ignore = false; 737 msg_idx++; 738 break; 739 740 default: 741 BUG(); 742 } 743 } else { 744 msg_idx++; 745 } 746 } 747 } 748 749 static void ads7846_report_state(struct ads7846 *ts) 750 { 751 struct ads7846_packet *packet = ts->packet; 752 unsigned int Rt; 753 u16 x, y, z1, z2; 754 755 /* 756 * ads7846_get_value() does in-place conversion (including byte swap) 757 * from on-the-wire format as part of debouncing to get stable 758 * readings. 759 */ 760 if (ts->model == 7845) { 761 x = *(u16 *)packet->tc.x_buf; 762 y = *(u16 *)packet->tc.y_buf; 763 z1 = 0; 764 z2 = 0; 765 } else { 766 x = packet->tc.x; 767 y = packet->tc.y; 768 z1 = packet->tc.z1; 769 z2 = packet->tc.z2; 770 } 771 772 /* range filtering */ 773 if (x == MAX_12BIT) 774 x = 0; 775 776 if (ts->model == 7843) { 777 Rt = ts->pressure_max / 2; 778 } else if (ts->model == 7845) { 779 if (get_pendown_state(ts)) 780 Rt = ts->pressure_max / 2; 781 else 782 Rt = 0; 783 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 784 } else if (likely(x && z1)) { 785 /* compute touch pressure resistance using equation #2 */ 786 Rt = z2; 787 Rt -= z1; 788 Rt *= x; 789 Rt *= ts->x_plate_ohms; 790 Rt /= z1; 791 Rt = (Rt + 2047) >> 12; 792 } else { 793 Rt = 0; 794 } 795 796 /* 797 * Sample found inconsistent by debouncing or pressure is beyond 798 * the maximum. Don't report it to user space, repeat at least 799 * once more the measurement 800 */ 801 if (packet->tc.ignore || Rt > ts->pressure_max) { 802 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 803 packet->tc.ignore, Rt); 804 return; 805 } 806 807 /* 808 * Maybe check the pendown state before reporting. This discards 809 * false readings when the pen is lifted. 810 */ 811 if (ts->penirq_recheck_delay_usecs) { 812 udelay(ts->penirq_recheck_delay_usecs); 813 if (!get_pendown_state(ts)) 814 Rt = 0; 815 } 816 817 /* 818 * NOTE: We can't rely on the pressure to determine the pen down 819 * state, even this controller has a pressure sensor. The pressure 820 * value can fluctuate for quite a while after lifting the pen and 821 * in some cases may not even settle at the expected value. 822 * 823 * The only safe way to check for the pen up condition is in the 824 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 825 */ 826 if (Rt) { 827 struct input_dev *input = ts->input; 828 829 if (ts->swap_xy) 830 swap(x, y); 831 832 if (!ts->pendown) { 833 input_report_key(input, BTN_TOUCH, 1); 834 ts->pendown = true; 835 dev_vdbg(&ts->spi->dev, "DOWN\n"); 836 } 837 838 input_report_abs(input, ABS_X, x); 839 input_report_abs(input, ABS_Y, y); 840 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 841 842 input_sync(input); 843 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 844 } 845 } 846 847 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 848 { 849 struct ads7846 *ts = handle; 850 851 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 852 } 853 854 855 static irqreturn_t ads7846_irq(int irq, void *handle) 856 { 857 struct ads7846 *ts = handle; 858 859 /* Start with a small delay before checking pendown state */ 860 msleep(TS_POLL_DELAY); 861 862 while (!ts->stopped && get_pendown_state(ts)) { 863 864 /* pen is down, continue with the measurement */ 865 ads7846_read_state(ts); 866 867 if (!ts->stopped) 868 ads7846_report_state(ts); 869 870 wait_event_timeout(ts->wait, ts->stopped, 871 msecs_to_jiffies(TS_POLL_PERIOD)); 872 } 873 874 if (ts->pendown) { 875 struct input_dev *input = ts->input; 876 877 input_report_key(input, BTN_TOUCH, 0); 878 input_report_abs(input, ABS_PRESSURE, 0); 879 input_sync(input); 880 881 ts->pendown = false; 882 dev_vdbg(&ts->spi->dev, "UP\n"); 883 } 884 885 return IRQ_HANDLED; 886 } 887 888 static int __maybe_unused ads7846_suspend(struct device *dev) 889 { 890 struct ads7846 *ts = dev_get_drvdata(dev); 891 892 mutex_lock(&ts->lock); 893 894 if (!ts->suspended) { 895 896 if (!ts->disabled) 897 __ads7846_disable(ts); 898 899 if (device_may_wakeup(&ts->spi->dev)) 900 enable_irq_wake(ts->spi->irq); 901 902 ts->suspended = true; 903 } 904 905 mutex_unlock(&ts->lock); 906 907 return 0; 908 } 909 910 static int __maybe_unused ads7846_resume(struct device *dev) 911 { 912 struct ads7846 *ts = dev_get_drvdata(dev); 913 914 mutex_lock(&ts->lock); 915 916 if (ts->suspended) { 917 918 ts->suspended = false; 919 920 if (device_may_wakeup(&ts->spi->dev)) 921 disable_irq_wake(ts->spi->irq); 922 923 if (!ts->disabled) 924 __ads7846_enable(ts); 925 } 926 927 mutex_unlock(&ts->lock); 928 929 return 0; 930 } 931 932 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 933 934 static int ads7846_setup_pendown(struct spi_device *spi, 935 struct ads7846 *ts, 936 const struct ads7846_platform_data *pdata) 937 { 938 int err; 939 940 /* 941 * REVISIT when the irq can be triggered active-low, or if for some 942 * reason the touchscreen isn't hooked up, we don't need to access 943 * the pendown state. 944 */ 945 946 if (pdata->get_pendown_state) { 947 ts->get_pendown_state = pdata->get_pendown_state; 948 } else if (gpio_is_valid(pdata->gpio_pendown)) { 949 950 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 951 "ads7846_pendown"); 952 if (err) { 953 dev_err(&spi->dev, 954 "failed to request/setup pendown GPIO%d: %d\n", 955 pdata->gpio_pendown, err); 956 return err; 957 } 958 959 ts->gpio_pendown = pdata->gpio_pendown; 960 961 if (pdata->gpio_pendown_debounce) 962 gpio_set_debounce(pdata->gpio_pendown, 963 pdata->gpio_pendown_debounce); 964 } else { 965 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 966 return -EINVAL; 967 } 968 969 return 0; 970 } 971 972 /* 973 * Set up the transfers to read touchscreen state; this assumes we 974 * use formula #2 for pressure, not #3. 975 */ 976 static void ads7846_setup_spi_msg(struct ads7846 *ts, 977 const struct ads7846_platform_data *pdata) 978 { 979 struct spi_message *m = &ts->msg[0]; 980 struct spi_transfer *x = ts->xfer; 981 struct ads7846_packet *packet = ts->packet; 982 int vref = pdata->keep_vref_on; 983 984 if (ts->model == 7873) { 985 /* 986 * The AD7873 is almost identical to the ADS7846 987 * keep VREF off during differential/ratiometric 988 * conversion modes. 989 */ 990 ts->model = 7846; 991 vref = 0; 992 } 993 994 ts->msg_count = 1; 995 spi_message_init(m); 996 m->context = ts; 997 998 if (ts->model == 7845) { 999 packet->read_y_cmd[0] = READ_Y(vref); 1000 packet->read_y_cmd[1] = 0; 1001 packet->read_y_cmd[2] = 0; 1002 x->tx_buf = &packet->read_y_cmd[0]; 1003 x->rx_buf = &packet->tc.y_buf[0]; 1004 x->len = 3; 1005 spi_message_add_tail(x, m); 1006 } else { 1007 /* y- still on; turn on only y+ (and ADC) */ 1008 packet->read_y = READ_Y(vref); 1009 x->tx_buf = &packet->read_y; 1010 x->len = 1; 1011 spi_message_add_tail(x, m); 1012 1013 x++; 1014 x->rx_buf = &packet->tc.y; 1015 x->len = 2; 1016 spi_message_add_tail(x, m); 1017 } 1018 1019 /* 1020 * The first sample after switching drivers can be low quality; 1021 * optionally discard it, using a second one after the signals 1022 * have had enough time to stabilize. 1023 */ 1024 if (pdata->settle_delay_usecs) { 1025 x->delay_usecs = pdata->settle_delay_usecs; 1026 1027 x++; 1028 x->tx_buf = &packet->read_y; 1029 x->len = 1; 1030 spi_message_add_tail(x, m); 1031 1032 x++; 1033 x->rx_buf = &packet->tc.y; 1034 x->len = 2; 1035 spi_message_add_tail(x, m); 1036 } 1037 1038 ts->msg_count++; 1039 m++; 1040 spi_message_init(m); 1041 m->context = ts; 1042 1043 if (ts->model == 7845) { 1044 x++; 1045 packet->read_x_cmd[0] = READ_X(vref); 1046 packet->read_x_cmd[1] = 0; 1047 packet->read_x_cmd[2] = 0; 1048 x->tx_buf = &packet->read_x_cmd[0]; 1049 x->rx_buf = &packet->tc.x_buf[0]; 1050 x->len = 3; 1051 spi_message_add_tail(x, m); 1052 } else { 1053 /* turn y- off, x+ on, then leave in lowpower */ 1054 x++; 1055 packet->read_x = READ_X(vref); 1056 x->tx_buf = &packet->read_x; 1057 x->len = 1; 1058 spi_message_add_tail(x, m); 1059 1060 x++; 1061 x->rx_buf = &packet->tc.x; 1062 x->len = 2; 1063 spi_message_add_tail(x, m); 1064 } 1065 1066 /* ... maybe discard first sample ... */ 1067 if (pdata->settle_delay_usecs) { 1068 x->delay_usecs = pdata->settle_delay_usecs; 1069 1070 x++; 1071 x->tx_buf = &packet->read_x; 1072 x->len = 1; 1073 spi_message_add_tail(x, m); 1074 1075 x++; 1076 x->rx_buf = &packet->tc.x; 1077 x->len = 2; 1078 spi_message_add_tail(x, m); 1079 } 1080 1081 /* turn y+ off, x- on; we'll use formula #2 */ 1082 if (ts->model == 7846) { 1083 ts->msg_count++; 1084 m++; 1085 spi_message_init(m); 1086 m->context = ts; 1087 1088 x++; 1089 packet->read_z1 = READ_Z1(vref); 1090 x->tx_buf = &packet->read_z1; 1091 x->len = 1; 1092 spi_message_add_tail(x, m); 1093 1094 x++; 1095 x->rx_buf = &packet->tc.z1; 1096 x->len = 2; 1097 spi_message_add_tail(x, m); 1098 1099 /* ... maybe discard first sample ... */ 1100 if (pdata->settle_delay_usecs) { 1101 x->delay_usecs = pdata->settle_delay_usecs; 1102 1103 x++; 1104 x->tx_buf = &packet->read_z1; 1105 x->len = 1; 1106 spi_message_add_tail(x, m); 1107 1108 x++; 1109 x->rx_buf = &packet->tc.z1; 1110 x->len = 2; 1111 spi_message_add_tail(x, m); 1112 } 1113 1114 ts->msg_count++; 1115 m++; 1116 spi_message_init(m); 1117 m->context = ts; 1118 1119 x++; 1120 packet->read_z2 = READ_Z2(vref); 1121 x->tx_buf = &packet->read_z2; 1122 x->len = 1; 1123 spi_message_add_tail(x, m); 1124 1125 x++; 1126 x->rx_buf = &packet->tc.z2; 1127 x->len = 2; 1128 spi_message_add_tail(x, m); 1129 1130 /* ... maybe discard first sample ... */ 1131 if (pdata->settle_delay_usecs) { 1132 x->delay_usecs = pdata->settle_delay_usecs; 1133 1134 x++; 1135 x->tx_buf = &packet->read_z2; 1136 x->len = 1; 1137 spi_message_add_tail(x, m); 1138 1139 x++; 1140 x->rx_buf = &packet->tc.z2; 1141 x->len = 2; 1142 spi_message_add_tail(x, m); 1143 } 1144 } 1145 1146 /* power down */ 1147 ts->msg_count++; 1148 m++; 1149 spi_message_init(m); 1150 m->context = ts; 1151 1152 if (ts->model == 7845) { 1153 x++; 1154 packet->pwrdown_cmd[0] = PWRDOWN; 1155 packet->pwrdown_cmd[1] = 0; 1156 packet->pwrdown_cmd[2] = 0; 1157 x->tx_buf = &packet->pwrdown_cmd[0]; 1158 x->len = 3; 1159 } else { 1160 x++; 1161 packet->pwrdown = PWRDOWN; 1162 x->tx_buf = &packet->pwrdown; 1163 x->len = 1; 1164 spi_message_add_tail(x, m); 1165 1166 x++; 1167 x->rx_buf = &packet->dummy; 1168 x->len = 2; 1169 } 1170 1171 CS_CHANGE(*x); 1172 spi_message_add_tail(x, m); 1173 } 1174 1175 #ifdef CONFIG_OF 1176 static const struct of_device_id ads7846_dt_ids[] = { 1177 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1178 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1179 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1180 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1181 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1182 { } 1183 }; 1184 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1185 1186 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1187 { 1188 struct ads7846_platform_data *pdata; 1189 struct device_node *node = dev->of_node; 1190 const struct of_device_id *match; 1191 1192 if (!node) { 1193 dev_err(dev, "Device does not have associated DT data\n"); 1194 return ERR_PTR(-EINVAL); 1195 } 1196 1197 match = of_match_device(ads7846_dt_ids, dev); 1198 if (!match) { 1199 dev_err(dev, "Unknown device model\n"); 1200 return ERR_PTR(-EINVAL); 1201 } 1202 1203 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1204 if (!pdata) 1205 return ERR_PTR(-ENOMEM); 1206 1207 pdata->model = (unsigned long)match->data; 1208 1209 of_property_read_u16(node, "ti,vref-delay-usecs", 1210 &pdata->vref_delay_usecs); 1211 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1212 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1213 1214 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1215 1216 of_property_read_u16(node, "ti,settle-delay-usec", 1217 &pdata->settle_delay_usecs); 1218 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1219 &pdata->penirq_recheck_delay_usecs); 1220 1221 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1222 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1223 1224 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1225 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1226 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1227 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1228 1229 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1230 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1231 1232 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1233 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1234 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1235 1236 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1237 &pdata->gpio_pendown_debounce); 1238 1239 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1240 of_property_read_bool(node, "linux,wakeup"); 1241 1242 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1243 1244 return pdata; 1245 } 1246 #else 1247 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1248 { 1249 dev_err(dev, "no platform data defined\n"); 1250 return ERR_PTR(-EINVAL); 1251 } 1252 #endif 1253 1254 static int ads7846_probe(struct spi_device *spi) 1255 { 1256 const struct ads7846_platform_data *pdata; 1257 struct ads7846 *ts; 1258 struct ads7846_packet *packet; 1259 struct input_dev *input_dev; 1260 unsigned long irq_flags; 1261 int err; 1262 1263 if (!spi->irq) { 1264 dev_dbg(&spi->dev, "no IRQ?\n"); 1265 return -EINVAL; 1266 } 1267 1268 /* don't exceed max specified sample rate */ 1269 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1270 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1271 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1272 return -EINVAL; 1273 } 1274 1275 /* 1276 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1277 * that even if the hardware can do that, the SPI controller driver 1278 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1279 */ 1280 spi->bits_per_word = 8; 1281 spi->mode = SPI_MODE_0; 1282 err = spi_setup(spi); 1283 if (err < 0) 1284 return err; 1285 1286 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1287 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1288 input_dev = input_allocate_device(); 1289 if (!ts || !packet || !input_dev) { 1290 err = -ENOMEM; 1291 goto err_free_mem; 1292 } 1293 1294 spi_set_drvdata(spi, ts); 1295 1296 ts->packet = packet; 1297 ts->spi = spi; 1298 ts->input = input_dev; 1299 1300 mutex_init(&ts->lock); 1301 init_waitqueue_head(&ts->wait); 1302 1303 pdata = dev_get_platdata(&spi->dev); 1304 if (!pdata) { 1305 pdata = ads7846_probe_dt(&spi->dev); 1306 if (IS_ERR(pdata)) { 1307 err = PTR_ERR(pdata); 1308 goto err_free_mem; 1309 } 1310 } 1311 1312 ts->model = pdata->model ? : 7846; 1313 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1314 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1315 ts->pressure_max = pdata->pressure_max ? : ~0; 1316 1317 ts->vref_mv = pdata->vref_mv; 1318 ts->swap_xy = pdata->swap_xy; 1319 1320 if (pdata->filter != NULL) { 1321 if (pdata->filter_init != NULL) { 1322 err = pdata->filter_init(pdata, &ts->filter_data); 1323 if (err < 0) 1324 goto err_free_mem; 1325 } 1326 ts->filter = pdata->filter; 1327 ts->filter_cleanup = pdata->filter_cleanup; 1328 } else if (pdata->debounce_max) { 1329 ts->debounce_max = pdata->debounce_max; 1330 if (ts->debounce_max < 2) 1331 ts->debounce_max = 2; 1332 ts->debounce_tol = pdata->debounce_tol; 1333 ts->debounce_rep = pdata->debounce_rep; 1334 ts->filter = ads7846_debounce_filter; 1335 ts->filter_data = ts; 1336 } else { 1337 ts->filter = ads7846_no_filter; 1338 } 1339 1340 err = ads7846_setup_pendown(spi, ts, pdata); 1341 if (err) 1342 goto err_cleanup_filter; 1343 1344 if (pdata->penirq_recheck_delay_usecs) 1345 ts->penirq_recheck_delay_usecs = 1346 pdata->penirq_recheck_delay_usecs; 1347 1348 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1349 1350 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1351 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1352 1353 input_dev->name = ts->name; 1354 input_dev->phys = ts->phys; 1355 input_dev->dev.parent = &spi->dev; 1356 1357 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1358 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1359 input_set_abs_params(input_dev, ABS_X, 1360 pdata->x_min ? : 0, 1361 pdata->x_max ? : MAX_12BIT, 1362 0, 0); 1363 input_set_abs_params(input_dev, ABS_Y, 1364 pdata->y_min ? : 0, 1365 pdata->y_max ? : MAX_12BIT, 1366 0, 0); 1367 input_set_abs_params(input_dev, ABS_PRESSURE, 1368 pdata->pressure_min, pdata->pressure_max, 0, 0); 1369 1370 ads7846_setup_spi_msg(ts, pdata); 1371 1372 ts->reg = regulator_get(&spi->dev, "vcc"); 1373 if (IS_ERR(ts->reg)) { 1374 err = PTR_ERR(ts->reg); 1375 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1376 goto err_free_gpio; 1377 } 1378 1379 err = regulator_enable(ts->reg); 1380 if (err) { 1381 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1382 goto err_put_regulator; 1383 } 1384 1385 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1386 irq_flags |= IRQF_ONESHOT; 1387 1388 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1389 irq_flags, spi->dev.driver->name, ts); 1390 if (err && !pdata->irq_flags) { 1391 dev_info(&spi->dev, 1392 "trying pin change workaround on irq %d\n", spi->irq); 1393 irq_flags |= IRQF_TRIGGER_RISING; 1394 err = request_threaded_irq(spi->irq, 1395 ads7846_hard_irq, ads7846_irq, 1396 irq_flags, spi->dev.driver->name, ts); 1397 } 1398 1399 if (err) { 1400 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1401 goto err_disable_regulator; 1402 } 1403 1404 err = ads784x_hwmon_register(spi, ts); 1405 if (err) 1406 goto err_free_irq; 1407 1408 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1409 1410 /* 1411 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1412 * the touchscreen, in case it's not connected. 1413 */ 1414 if (ts->model == 7845) 1415 ads7845_read12_ser(&spi->dev, PWRDOWN); 1416 else 1417 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1418 1419 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1420 if (err) 1421 goto err_remove_hwmon; 1422 1423 err = input_register_device(input_dev); 1424 if (err) 1425 goto err_remove_attr_group; 1426 1427 device_init_wakeup(&spi->dev, pdata->wakeup); 1428 1429 /* 1430 * If device does not carry platform data we must have allocated it 1431 * when parsing DT data. 1432 */ 1433 if (!dev_get_platdata(&spi->dev)) 1434 devm_kfree(&spi->dev, (void *)pdata); 1435 1436 return 0; 1437 1438 err_remove_attr_group: 1439 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1440 err_remove_hwmon: 1441 ads784x_hwmon_unregister(spi, ts); 1442 err_free_irq: 1443 free_irq(spi->irq, ts); 1444 err_disable_regulator: 1445 regulator_disable(ts->reg); 1446 err_put_regulator: 1447 regulator_put(ts->reg); 1448 err_free_gpio: 1449 if (!ts->get_pendown_state) 1450 gpio_free(ts->gpio_pendown); 1451 err_cleanup_filter: 1452 if (ts->filter_cleanup) 1453 ts->filter_cleanup(ts->filter_data); 1454 err_free_mem: 1455 input_free_device(input_dev); 1456 kfree(packet); 1457 kfree(ts); 1458 return err; 1459 } 1460 1461 static int ads7846_remove(struct spi_device *spi) 1462 { 1463 struct ads7846 *ts = spi_get_drvdata(spi); 1464 1465 device_init_wakeup(&spi->dev, false); 1466 1467 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1468 1469 ads7846_disable(ts); 1470 free_irq(ts->spi->irq, ts); 1471 1472 input_unregister_device(ts->input); 1473 1474 ads784x_hwmon_unregister(spi, ts); 1475 1476 regulator_disable(ts->reg); 1477 regulator_put(ts->reg); 1478 1479 if (!ts->get_pendown_state) { 1480 /* 1481 * If we are not using specialized pendown method we must 1482 * have been relying on gpio we set up ourselves. 1483 */ 1484 gpio_free(ts->gpio_pendown); 1485 } 1486 1487 if (ts->filter_cleanup) 1488 ts->filter_cleanup(ts->filter_data); 1489 1490 kfree(ts->packet); 1491 kfree(ts); 1492 1493 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1494 1495 return 0; 1496 } 1497 1498 static struct spi_driver ads7846_driver = { 1499 .driver = { 1500 .name = "ads7846", 1501 .pm = &ads7846_pm, 1502 .of_match_table = of_match_ptr(ads7846_dt_ids), 1503 }, 1504 .probe = ads7846_probe, 1505 .remove = ads7846_remove, 1506 }; 1507 1508 module_spi_driver(ads7846_driver); 1509 1510 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1511 MODULE_LICENSE("GPL"); 1512 MODULE_ALIAS("spi:ads7846"); 1513