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 if (IS_ERR(ts->hwmon)) 533 return PTR_ERR(ts->hwmon); 534 535 return 0; 536 } 537 538 static void ads784x_hwmon_unregister(struct spi_device *spi, 539 struct ads7846 *ts) 540 { 541 if (ts->hwmon) 542 hwmon_device_unregister(ts->hwmon); 543 } 544 545 #else 546 static inline int ads784x_hwmon_register(struct spi_device *spi, 547 struct ads7846 *ts) 548 { 549 return 0; 550 } 551 552 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 553 struct ads7846 *ts) 554 { 555 } 556 #endif 557 558 static ssize_t ads7846_pen_down_show(struct device *dev, 559 struct device_attribute *attr, char *buf) 560 { 561 struct ads7846 *ts = dev_get_drvdata(dev); 562 563 return sprintf(buf, "%u\n", ts->pendown); 564 } 565 566 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 567 568 static ssize_t ads7846_disable_show(struct device *dev, 569 struct device_attribute *attr, char *buf) 570 { 571 struct ads7846 *ts = dev_get_drvdata(dev); 572 573 return sprintf(buf, "%u\n", ts->disabled); 574 } 575 576 static ssize_t ads7846_disable_store(struct device *dev, 577 struct device_attribute *attr, 578 const char *buf, size_t count) 579 { 580 struct ads7846 *ts = dev_get_drvdata(dev); 581 unsigned int i; 582 int err; 583 584 err = kstrtouint(buf, 10, &i); 585 if (err) 586 return err; 587 588 if (i) 589 ads7846_disable(ts); 590 else 591 ads7846_enable(ts); 592 593 return count; 594 } 595 596 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 597 598 static struct attribute *ads784x_attributes[] = { 599 &dev_attr_pen_down.attr, 600 &dev_attr_disable.attr, 601 NULL, 602 }; 603 604 static struct attribute_group ads784x_attr_group = { 605 .attrs = ads784x_attributes, 606 }; 607 608 /*--------------------------------------------------------------------------*/ 609 610 static int get_pendown_state(struct ads7846 *ts) 611 { 612 if (ts->get_pendown_state) 613 return ts->get_pendown_state(); 614 615 return !gpio_get_value(ts->gpio_pendown); 616 } 617 618 static void null_wait_for_sync(void) 619 { 620 } 621 622 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 623 { 624 struct ads7846 *ts = ads; 625 626 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 627 /* Start over collecting consistent readings. */ 628 ts->read_rep = 0; 629 /* 630 * Repeat it, if this was the first read or the read 631 * wasn't consistent enough. 632 */ 633 if (ts->read_cnt < ts->debounce_max) { 634 ts->last_read = *val; 635 ts->read_cnt++; 636 return ADS7846_FILTER_REPEAT; 637 } else { 638 /* 639 * Maximum number of debouncing reached and still 640 * not enough number of consistent readings. Abort 641 * the whole sample, repeat it in the next sampling 642 * period. 643 */ 644 ts->read_cnt = 0; 645 return ADS7846_FILTER_IGNORE; 646 } 647 } else { 648 if (++ts->read_rep > ts->debounce_rep) { 649 /* 650 * Got a good reading for this coordinate, 651 * go for the next one. 652 */ 653 ts->read_cnt = 0; 654 ts->read_rep = 0; 655 return ADS7846_FILTER_OK; 656 } else { 657 /* Read more values that are consistent. */ 658 ts->read_cnt++; 659 return ADS7846_FILTER_REPEAT; 660 } 661 } 662 } 663 664 static int ads7846_no_filter(void *ads, int data_idx, int *val) 665 { 666 return ADS7846_FILTER_OK; 667 } 668 669 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 670 { 671 struct spi_transfer *t = 672 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 673 674 if (ts->model == 7845) { 675 return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3; 676 } else { 677 /* 678 * adjust: on-wire is a must-ignore bit, a BE12 value, then 679 * padding; built from two 8 bit values written msb-first. 680 */ 681 return be16_to_cpup((__be16 *)t->rx_buf) >> 3; 682 } 683 } 684 685 static void ads7846_update_value(struct spi_message *m, int val) 686 { 687 struct spi_transfer *t = 688 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 689 690 *(u16 *)t->rx_buf = val; 691 } 692 693 static void ads7846_read_state(struct ads7846 *ts) 694 { 695 struct ads7846_packet *packet = ts->packet; 696 struct spi_message *m; 697 int msg_idx = 0; 698 int val; 699 int action; 700 int error; 701 702 while (msg_idx < ts->msg_count) { 703 704 ts->wait_for_sync(); 705 706 m = &ts->msg[msg_idx]; 707 error = spi_sync(ts->spi, m); 708 if (error) { 709 dev_err(&ts->spi->dev, "spi_async --> %d\n", error); 710 packet->tc.ignore = true; 711 return; 712 } 713 714 /* 715 * Last message is power down request, no need to convert 716 * or filter the value. 717 */ 718 if (msg_idx < ts->msg_count - 1) { 719 720 val = ads7846_get_value(ts, m); 721 722 action = ts->filter(ts->filter_data, msg_idx, &val); 723 switch (action) { 724 case ADS7846_FILTER_REPEAT: 725 continue; 726 727 case ADS7846_FILTER_IGNORE: 728 packet->tc.ignore = true; 729 msg_idx = ts->msg_count - 1; 730 continue; 731 732 case ADS7846_FILTER_OK: 733 ads7846_update_value(m, val); 734 packet->tc.ignore = false; 735 msg_idx++; 736 break; 737 738 default: 739 BUG(); 740 } 741 } else { 742 msg_idx++; 743 } 744 } 745 } 746 747 static void ads7846_report_state(struct ads7846 *ts) 748 { 749 struct ads7846_packet *packet = ts->packet; 750 unsigned int Rt; 751 u16 x, y, z1, z2; 752 753 /* 754 * ads7846_get_value() does in-place conversion (including byte swap) 755 * from on-the-wire format as part of debouncing to get stable 756 * readings. 757 */ 758 if (ts->model == 7845) { 759 x = *(u16 *)packet->tc.x_buf; 760 y = *(u16 *)packet->tc.y_buf; 761 z1 = 0; 762 z2 = 0; 763 } else { 764 x = packet->tc.x; 765 y = packet->tc.y; 766 z1 = packet->tc.z1; 767 z2 = packet->tc.z2; 768 } 769 770 /* range filtering */ 771 if (x == MAX_12BIT) 772 x = 0; 773 774 if (ts->model == 7843) { 775 Rt = ts->pressure_max / 2; 776 } else if (ts->model == 7845) { 777 if (get_pendown_state(ts)) 778 Rt = ts->pressure_max / 2; 779 else 780 Rt = 0; 781 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 782 } else if (likely(x && z1)) { 783 /* compute touch pressure resistance using equation #2 */ 784 Rt = z2; 785 Rt -= z1; 786 Rt *= x; 787 Rt *= ts->x_plate_ohms; 788 Rt /= z1; 789 Rt = (Rt + 2047) >> 12; 790 } else { 791 Rt = 0; 792 } 793 794 /* 795 * Sample found inconsistent by debouncing or pressure is beyond 796 * the maximum. Don't report it to user space, repeat at least 797 * once more the measurement 798 */ 799 if (packet->tc.ignore || Rt > ts->pressure_max) { 800 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 801 packet->tc.ignore, Rt); 802 return; 803 } 804 805 /* 806 * Maybe check the pendown state before reporting. This discards 807 * false readings when the pen is lifted. 808 */ 809 if (ts->penirq_recheck_delay_usecs) { 810 udelay(ts->penirq_recheck_delay_usecs); 811 if (!get_pendown_state(ts)) 812 Rt = 0; 813 } 814 815 /* 816 * NOTE: We can't rely on the pressure to determine the pen down 817 * state, even this controller has a pressure sensor. The pressure 818 * value can fluctuate for quite a while after lifting the pen and 819 * in some cases may not even settle at the expected value. 820 * 821 * The only safe way to check for the pen up condition is in the 822 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 823 */ 824 if (Rt) { 825 struct input_dev *input = ts->input; 826 827 if (ts->swap_xy) 828 swap(x, y); 829 830 if (!ts->pendown) { 831 input_report_key(input, BTN_TOUCH, 1); 832 ts->pendown = true; 833 dev_vdbg(&ts->spi->dev, "DOWN\n"); 834 } 835 836 input_report_abs(input, ABS_X, x); 837 input_report_abs(input, ABS_Y, y); 838 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 839 840 input_sync(input); 841 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 842 } 843 } 844 845 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 846 { 847 struct ads7846 *ts = handle; 848 849 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 850 } 851 852 853 static irqreturn_t ads7846_irq(int irq, void *handle) 854 { 855 struct ads7846 *ts = handle; 856 857 /* Start with a small delay before checking pendown state */ 858 msleep(TS_POLL_DELAY); 859 860 while (!ts->stopped && get_pendown_state(ts)) { 861 862 /* pen is down, continue with the measurement */ 863 ads7846_read_state(ts); 864 865 if (!ts->stopped) 866 ads7846_report_state(ts); 867 868 wait_event_timeout(ts->wait, ts->stopped, 869 msecs_to_jiffies(TS_POLL_PERIOD)); 870 } 871 872 if (ts->pendown) { 873 struct input_dev *input = ts->input; 874 875 input_report_key(input, BTN_TOUCH, 0); 876 input_report_abs(input, ABS_PRESSURE, 0); 877 input_sync(input); 878 879 ts->pendown = false; 880 dev_vdbg(&ts->spi->dev, "UP\n"); 881 } 882 883 return IRQ_HANDLED; 884 } 885 886 #ifdef CONFIG_PM_SLEEP 887 static int ads7846_suspend(struct device *dev) 888 { 889 struct ads7846 *ts = dev_get_drvdata(dev); 890 891 mutex_lock(&ts->lock); 892 893 if (!ts->suspended) { 894 895 if (!ts->disabled) 896 __ads7846_disable(ts); 897 898 if (device_may_wakeup(&ts->spi->dev)) 899 enable_irq_wake(ts->spi->irq); 900 901 ts->suspended = true; 902 } 903 904 mutex_unlock(&ts->lock); 905 906 return 0; 907 } 908 909 static int ads7846_resume(struct device *dev) 910 { 911 struct ads7846 *ts = dev_get_drvdata(dev); 912 913 mutex_lock(&ts->lock); 914 915 if (ts->suspended) { 916 917 ts->suspended = false; 918 919 if (device_may_wakeup(&ts->spi->dev)) 920 disable_irq_wake(ts->spi->irq); 921 922 if (!ts->disabled) 923 __ads7846_enable(ts); 924 } 925 926 mutex_unlock(&ts->lock); 927 928 return 0; 929 } 930 #endif 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, "linux,wakeup"); 1240 1241 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1242 1243 return pdata; 1244 } 1245 #else 1246 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1247 { 1248 dev_err(dev, "no platform data defined\n"); 1249 return ERR_PTR(-EINVAL); 1250 } 1251 #endif 1252 1253 static int ads7846_probe(struct spi_device *spi) 1254 { 1255 const struct ads7846_platform_data *pdata; 1256 struct ads7846 *ts; 1257 struct ads7846_packet *packet; 1258 struct input_dev *input_dev; 1259 unsigned long irq_flags; 1260 int err; 1261 1262 if (!spi->irq) { 1263 dev_dbg(&spi->dev, "no IRQ?\n"); 1264 return -EINVAL; 1265 } 1266 1267 /* don't exceed max specified sample rate */ 1268 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1269 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1270 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1271 return -EINVAL; 1272 } 1273 1274 /* 1275 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1276 * that even if the hardware can do that, the SPI controller driver 1277 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1278 */ 1279 spi->bits_per_word = 8; 1280 spi->mode = SPI_MODE_0; 1281 err = spi_setup(spi); 1282 if (err < 0) 1283 return err; 1284 1285 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1286 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1287 input_dev = input_allocate_device(); 1288 if (!ts || !packet || !input_dev) { 1289 err = -ENOMEM; 1290 goto err_free_mem; 1291 } 1292 1293 spi_set_drvdata(spi, ts); 1294 1295 ts->packet = packet; 1296 ts->spi = spi; 1297 ts->input = input_dev; 1298 1299 mutex_init(&ts->lock); 1300 init_waitqueue_head(&ts->wait); 1301 1302 pdata = dev_get_platdata(&spi->dev); 1303 if (!pdata) { 1304 pdata = ads7846_probe_dt(&spi->dev); 1305 if (IS_ERR(pdata)) 1306 return PTR_ERR(pdata); 1307 } 1308 1309 ts->model = pdata->model ? : 7846; 1310 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1311 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1312 ts->pressure_max = pdata->pressure_max ? : ~0; 1313 1314 ts->vref_mv = pdata->vref_mv; 1315 ts->swap_xy = pdata->swap_xy; 1316 1317 if (pdata->filter != NULL) { 1318 if (pdata->filter_init != NULL) { 1319 err = pdata->filter_init(pdata, &ts->filter_data); 1320 if (err < 0) 1321 goto err_free_mem; 1322 } 1323 ts->filter = pdata->filter; 1324 ts->filter_cleanup = pdata->filter_cleanup; 1325 } else if (pdata->debounce_max) { 1326 ts->debounce_max = pdata->debounce_max; 1327 if (ts->debounce_max < 2) 1328 ts->debounce_max = 2; 1329 ts->debounce_tol = pdata->debounce_tol; 1330 ts->debounce_rep = pdata->debounce_rep; 1331 ts->filter = ads7846_debounce_filter; 1332 ts->filter_data = ts; 1333 } else { 1334 ts->filter = ads7846_no_filter; 1335 } 1336 1337 err = ads7846_setup_pendown(spi, ts, pdata); 1338 if (err) 1339 goto err_cleanup_filter; 1340 1341 if (pdata->penirq_recheck_delay_usecs) 1342 ts->penirq_recheck_delay_usecs = 1343 pdata->penirq_recheck_delay_usecs; 1344 1345 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1346 1347 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1348 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1349 1350 input_dev->name = ts->name; 1351 input_dev->phys = ts->phys; 1352 input_dev->dev.parent = &spi->dev; 1353 1354 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1355 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1356 input_set_abs_params(input_dev, ABS_X, 1357 pdata->x_min ? : 0, 1358 pdata->x_max ? : MAX_12BIT, 1359 0, 0); 1360 input_set_abs_params(input_dev, ABS_Y, 1361 pdata->y_min ? : 0, 1362 pdata->y_max ? : MAX_12BIT, 1363 0, 0); 1364 input_set_abs_params(input_dev, ABS_PRESSURE, 1365 pdata->pressure_min, pdata->pressure_max, 0, 0); 1366 1367 ads7846_setup_spi_msg(ts, pdata); 1368 1369 ts->reg = regulator_get(&spi->dev, "vcc"); 1370 if (IS_ERR(ts->reg)) { 1371 err = PTR_ERR(ts->reg); 1372 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1373 goto err_free_gpio; 1374 } 1375 1376 err = regulator_enable(ts->reg); 1377 if (err) { 1378 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1379 goto err_put_regulator; 1380 } 1381 1382 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1383 irq_flags |= IRQF_ONESHOT; 1384 1385 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1386 irq_flags, spi->dev.driver->name, ts); 1387 if (err && !pdata->irq_flags) { 1388 dev_info(&spi->dev, 1389 "trying pin change workaround on irq %d\n", spi->irq); 1390 irq_flags |= IRQF_TRIGGER_RISING; 1391 err = request_threaded_irq(spi->irq, 1392 ads7846_hard_irq, ads7846_irq, 1393 irq_flags, spi->dev.driver->name, ts); 1394 } 1395 1396 if (err) { 1397 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1398 goto err_disable_regulator; 1399 } 1400 1401 err = ads784x_hwmon_register(spi, ts); 1402 if (err) 1403 goto err_free_irq; 1404 1405 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1406 1407 /* 1408 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1409 * the touchscreen, in case it's not connected. 1410 */ 1411 if (ts->model == 7845) 1412 ads7845_read12_ser(&spi->dev, PWRDOWN); 1413 else 1414 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1415 1416 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1417 if (err) 1418 goto err_remove_hwmon; 1419 1420 err = input_register_device(input_dev); 1421 if (err) 1422 goto err_remove_attr_group; 1423 1424 device_init_wakeup(&spi->dev, pdata->wakeup); 1425 1426 /* 1427 * If device does not carry platform data we must have allocated it 1428 * when parsing DT data. 1429 */ 1430 if (!dev_get_platdata(&spi->dev)) 1431 devm_kfree(&spi->dev, (void *)pdata); 1432 1433 return 0; 1434 1435 err_remove_attr_group: 1436 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1437 err_remove_hwmon: 1438 ads784x_hwmon_unregister(spi, ts); 1439 err_free_irq: 1440 free_irq(spi->irq, ts); 1441 err_disable_regulator: 1442 regulator_disable(ts->reg); 1443 err_put_regulator: 1444 regulator_put(ts->reg); 1445 err_free_gpio: 1446 if (!ts->get_pendown_state) 1447 gpio_free(ts->gpio_pendown); 1448 err_cleanup_filter: 1449 if (ts->filter_cleanup) 1450 ts->filter_cleanup(ts->filter_data); 1451 err_free_mem: 1452 input_free_device(input_dev); 1453 kfree(packet); 1454 kfree(ts); 1455 return err; 1456 } 1457 1458 static int ads7846_remove(struct spi_device *spi) 1459 { 1460 struct ads7846 *ts = spi_get_drvdata(spi); 1461 1462 device_init_wakeup(&spi->dev, false); 1463 1464 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1465 1466 ads7846_disable(ts); 1467 free_irq(ts->spi->irq, ts); 1468 1469 input_unregister_device(ts->input); 1470 1471 ads784x_hwmon_unregister(spi, ts); 1472 1473 regulator_disable(ts->reg); 1474 regulator_put(ts->reg); 1475 1476 if (!ts->get_pendown_state) { 1477 /* 1478 * If we are not using specialized pendown method we must 1479 * have been relying on gpio we set up ourselves. 1480 */ 1481 gpio_free(ts->gpio_pendown); 1482 } 1483 1484 if (ts->filter_cleanup) 1485 ts->filter_cleanup(ts->filter_data); 1486 1487 kfree(ts->packet); 1488 kfree(ts); 1489 1490 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1491 1492 return 0; 1493 } 1494 1495 static struct spi_driver ads7846_driver = { 1496 .driver = { 1497 .name = "ads7846", 1498 .owner = THIS_MODULE, 1499 .pm = &ads7846_pm, 1500 .of_match_table = of_match_ptr(ads7846_dt_ids), 1501 }, 1502 .probe = ads7846_probe, 1503 .remove = ads7846_remove, 1504 }; 1505 1506 module_spi_driver(ads7846_driver); 1507 1508 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1509 MODULE_LICENSE("GPL"); 1510 MODULE_ALIAS("spi:ads7846"); 1511