1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ADS7846 based touchscreen and sensor driver 4 * 5 * Copyright (c) 2005 David Brownell 6 * Copyright (c) 2006 Nokia Corporation 7 * Various changes: Imre Deak <imre.deak@nokia.com> 8 * 9 * Using code from: 10 * - corgi_ts.c 11 * Copyright (C) 2004-2005 Richard Purdie 12 * - omap_ts.[hc], ads7846.h, ts_osk.c 13 * Copyright (C) 2002 MontaVista Software 14 * Copyright (C) 2004 Texas Instruments 15 * Copyright (C) 2005 Dirk Behme 16 */ 17 #include <linux/types.h> 18 #include <linux/hwmon.h> 19 #include <linux/err.h> 20 #include <linux/sched.h> 21 #include <linux/delay.h> 22 #include <linux/input.h> 23 #include <linux/input/touchscreen.h> 24 #include <linux/interrupt.h> 25 #include <linux/slab.h> 26 #include <linux/pm.h> 27 #include <linux/of.h> 28 #include <linux/of_gpio.h> 29 #include <linux/of_device.h> 30 #include <linux/gpio.h> 31 #include <linux/spi/spi.h> 32 #include <linux/spi/ads7846.h> 33 #include <linux/regulator/consumer.h> 34 #include <linux/module.h> 35 #include <asm/irq.h> 36 #include <asm/unaligned.h> 37 38 /* 39 * This code has been heavily tested on a Nokia 770, and lightly 40 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 41 * TSC2046 is just newer ads7846 silicon. 42 * Support for ads7843 tested on Atmel at91sam926x-EK. 43 * Support for ads7845 has only been stubbed in. 44 * Support for Analog Devices AD7873 and AD7843 tested. 45 * 46 * IRQ handling needs a workaround because of a shortcoming in handling 47 * edge triggered IRQs on some platforms like the OMAP1/2. These 48 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 49 * have to maintain our own SW IRQ disabled status. This should be 50 * removed as soon as the affected platform's IRQ handling is fixed. 51 * 52 * App note sbaa036 talks in more detail about accurate sampling... 53 * that ought to help in situations like LCDs inducing noise (which 54 * can also be helped by using synch signals) and more generally. 55 * This driver tries to utilize the measures described in the app 56 * note. The strength of filtering can be set in the board-* specific 57 * files. 58 */ 59 60 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 61 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 62 63 /* this driver doesn't aim at the peak continuous sample rate */ 64 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 65 66 struct ads7846_buf { 67 u8 cmd; 68 /* 69 * This union is a temporary hack. The driver does an in-place 70 * endianness conversion. This will be cleaned up in the next 71 * patch. 72 */ 73 union { 74 __be16 data_be16; 75 u16 data; 76 }; 77 } __packed; 78 79 80 struct ts_event { 81 bool ignore; 82 struct ads7846_buf x; 83 struct ads7846_buf y; 84 struct ads7846_buf z1; 85 struct ads7846_buf z2; 86 }; 87 88 /* 89 * We allocate this separately to avoid cache line sharing issues when 90 * driver is used with DMA-based SPI controllers (like atmel_spi) on 91 * systems where main memory is not DMA-coherent (most non-x86 boards). 92 */ 93 struct ads7846_packet { 94 struct ts_event tc; 95 struct ads7846_buf read_x_cmd; 96 struct ads7846_buf read_y_cmd; 97 struct ads7846_buf read_z1_cmd; 98 struct ads7846_buf read_z2_cmd; 99 struct ads7846_buf pwrdown_cmd; 100 }; 101 102 struct ads7846 { 103 struct input_dev *input; 104 char phys[32]; 105 char name[32]; 106 107 struct spi_device *spi; 108 struct regulator *reg; 109 110 #if IS_ENABLED(CONFIG_HWMON) 111 struct device *hwmon; 112 #endif 113 114 u16 model; 115 u16 vref_mv; 116 u16 vref_delay_usecs; 117 u16 x_plate_ohms; 118 u16 pressure_max; 119 120 bool swap_xy; 121 bool use_internal; 122 123 struct ads7846_packet *packet; 124 125 struct spi_transfer xfer[18]; 126 struct spi_message msg[5]; 127 int msg_count; 128 wait_queue_head_t wait; 129 130 bool pendown; 131 132 int read_cnt; 133 int read_rep; 134 int last_read; 135 136 u16 debounce_max; 137 u16 debounce_tol; 138 u16 debounce_rep; 139 140 u16 penirq_recheck_delay_usecs; 141 142 struct touchscreen_properties core_prop; 143 144 struct mutex lock; 145 bool stopped; /* P: lock */ 146 bool disabled; /* P: lock */ 147 bool suspended; /* P: lock */ 148 149 int (*filter)(void *data, int data_idx, int *val); 150 void *filter_data; 151 void (*filter_cleanup)(void *data); 152 int (*get_pendown_state)(void); 153 int gpio_pendown; 154 155 void (*wait_for_sync)(void); 156 }; 157 158 /* leave chip selected when we're done, for quicker re-select? */ 159 #if 0 160 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 161 #else 162 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 163 #endif 164 165 /*--------------------------------------------------------------------------*/ 166 167 /* The ADS7846 has touchscreen and other sensors. 168 * Earlier ads784x chips are somewhat compatible. 169 */ 170 #define ADS_START (1 << 7) 171 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 172 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 173 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 174 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 175 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 176 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 177 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 178 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 179 #define ADS_8_BIT (1 << 3) 180 #define ADS_12_BIT (0 << 3) 181 #define ADS_SER (1 << 2) /* non-differential */ 182 #define ADS_DFR (0 << 2) /* differential */ 183 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 184 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 185 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 186 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 187 188 #define MAX_12BIT ((1<<12)-1) 189 190 /* leave ADC powered up (disables penirq) between differential samples */ 191 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 192 | ADS_12_BIT | ADS_DFR | \ 193 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 194 195 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 196 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 197 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 198 199 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 200 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 201 202 /* single-ended samples need to first power up reference voltage; 203 * we leave both ADC and VREF powered 204 */ 205 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 206 | ADS_12_BIT | ADS_SER) 207 208 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 209 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 210 211 static int get_pendown_state(struct ads7846 *ts) 212 { 213 if (ts->get_pendown_state) 214 return ts->get_pendown_state(); 215 216 return !gpio_get_value(ts->gpio_pendown); 217 } 218 219 static void ads7846_report_pen_up(struct ads7846 *ts) 220 { 221 struct input_dev *input = ts->input; 222 223 input_report_key(input, BTN_TOUCH, 0); 224 input_report_abs(input, ABS_PRESSURE, 0); 225 input_sync(input); 226 227 ts->pendown = false; 228 dev_vdbg(&ts->spi->dev, "UP\n"); 229 } 230 231 /* Must be called with ts->lock held */ 232 static void ads7846_stop(struct ads7846 *ts) 233 { 234 if (!ts->disabled && !ts->suspended) { 235 /* Signal IRQ thread to stop polling and disable the handler. */ 236 ts->stopped = true; 237 mb(); 238 wake_up(&ts->wait); 239 disable_irq(ts->spi->irq); 240 } 241 } 242 243 /* Must be called with ts->lock held */ 244 static void ads7846_restart(struct ads7846 *ts) 245 { 246 if (!ts->disabled && !ts->suspended) { 247 /* Check if pen was released since last stop */ 248 if (ts->pendown && !get_pendown_state(ts)) 249 ads7846_report_pen_up(ts); 250 251 /* Tell IRQ thread that it may poll the device. */ 252 ts->stopped = false; 253 mb(); 254 enable_irq(ts->spi->irq); 255 } 256 } 257 258 /* Must be called with ts->lock held */ 259 static void __ads7846_disable(struct ads7846 *ts) 260 { 261 ads7846_stop(ts); 262 regulator_disable(ts->reg); 263 264 /* 265 * We know the chip's in low power mode since we always 266 * leave it that way after every request 267 */ 268 } 269 270 /* Must be called with ts->lock held */ 271 static void __ads7846_enable(struct ads7846 *ts) 272 { 273 int error; 274 275 error = regulator_enable(ts->reg); 276 if (error != 0) 277 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 278 279 ads7846_restart(ts); 280 } 281 282 static void ads7846_disable(struct ads7846 *ts) 283 { 284 mutex_lock(&ts->lock); 285 286 if (!ts->disabled) { 287 288 if (!ts->suspended) 289 __ads7846_disable(ts); 290 291 ts->disabled = true; 292 } 293 294 mutex_unlock(&ts->lock); 295 } 296 297 static void ads7846_enable(struct ads7846 *ts) 298 { 299 mutex_lock(&ts->lock); 300 301 if (ts->disabled) { 302 303 ts->disabled = false; 304 305 if (!ts->suspended) 306 __ads7846_enable(ts); 307 } 308 309 mutex_unlock(&ts->lock); 310 } 311 312 /*--------------------------------------------------------------------------*/ 313 314 /* 315 * Non-touchscreen sensors only use single-ended conversions. 316 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 317 * ads7846 lets that pin be unconnected, to use internal vREF. 318 */ 319 320 struct ser_req { 321 u8 ref_on; 322 u8 command; 323 u8 ref_off; 324 u16 scratch; 325 struct spi_message msg; 326 struct spi_transfer xfer[6]; 327 /* 328 * DMA (thus cache coherency maintenance) requires the 329 * transfer buffers to live in their own cache lines. 330 */ 331 __be16 sample ____cacheline_aligned; 332 }; 333 334 struct ads7845_ser_req { 335 u8 command[3]; 336 struct spi_message msg; 337 struct spi_transfer xfer[2]; 338 /* 339 * DMA (thus cache coherency maintenance) requires the 340 * transfer buffers to live in their own cache lines. 341 */ 342 u8 sample[3] ____cacheline_aligned; 343 }; 344 345 static int ads7846_read12_ser(struct device *dev, unsigned command) 346 { 347 struct spi_device *spi = to_spi_device(dev); 348 struct ads7846 *ts = dev_get_drvdata(dev); 349 struct ser_req *req; 350 int status; 351 352 req = kzalloc(sizeof *req, GFP_KERNEL); 353 if (!req) 354 return -ENOMEM; 355 356 spi_message_init(&req->msg); 357 358 /* maybe turn on internal vREF, and let it settle */ 359 if (ts->use_internal) { 360 req->ref_on = REF_ON; 361 req->xfer[0].tx_buf = &req->ref_on; 362 req->xfer[0].len = 1; 363 spi_message_add_tail(&req->xfer[0], &req->msg); 364 365 req->xfer[1].rx_buf = &req->scratch; 366 req->xfer[1].len = 2; 367 368 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 369 req->xfer[1].delay.value = ts->vref_delay_usecs; 370 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 371 spi_message_add_tail(&req->xfer[1], &req->msg); 372 373 /* Enable reference voltage */ 374 command |= ADS_PD10_REF_ON; 375 } 376 377 /* Enable ADC in every case */ 378 command |= ADS_PD10_ADC_ON; 379 380 /* take sample */ 381 req->command = (u8) command; 382 req->xfer[2].tx_buf = &req->command; 383 req->xfer[2].len = 1; 384 spi_message_add_tail(&req->xfer[2], &req->msg); 385 386 req->xfer[3].rx_buf = &req->sample; 387 req->xfer[3].len = 2; 388 spi_message_add_tail(&req->xfer[3], &req->msg); 389 390 /* REVISIT: take a few more samples, and compare ... */ 391 392 /* converter in low power mode & enable PENIRQ */ 393 req->ref_off = PWRDOWN; 394 req->xfer[4].tx_buf = &req->ref_off; 395 req->xfer[4].len = 1; 396 spi_message_add_tail(&req->xfer[4], &req->msg); 397 398 req->xfer[5].rx_buf = &req->scratch; 399 req->xfer[5].len = 2; 400 CS_CHANGE(req->xfer[5]); 401 spi_message_add_tail(&req->xfer[5], &req->msg); 402 403 mutex_lock(&ts->lock); 404 ads7846_stop(ts); 405 status = spi_sync(spi, &req->msg); 406 ads7846_restart(ts); 407 mutex_unlock(&ts->lock); 408 409 if (status == 0) { 410 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 411 status = be16_to_cpu(req->sample); 412 status = status >> 3; 413 status &= 0x0fff; 414 } 415 416 kfree(req); 417 return status; 418 } 419 420 static int ads7845_read12_ser(struct device *dev, unsigned command) 421 { 422 struct spi_device *spi = to_spi_device(dev); 423 struct ads7846 *ts = dev_get_drvdata(dev); 424 struct ads7845_ser_req *req; 425 int status; 426 427 req = kzalloc(sizeof *req, GFP_KERNEL); 428 if (!req) 429 return -ENOMEM; 430 431 spi_message_init(&req->msg); 432 433 req->command[0] = (u8) command; 434 req->xfer[0].tx_buf = req->command; 435 req->xfer[0].rx_buf = req->sample; 436 req->xfer[0].len = 3; 437 spi_message_add_tail(&req->xfer[0], &req->msg); 438 439 mutex_lock(&ts->lock); 440 ads7846_stop(ts); 441 status = spi_sync(spi, &req->msg); 442 ads7846_restart(ts); 443 mutex_unlock(&ts->lock); 444 445 if (status == 0) { 446 /* BE12 value, then padding */ 447 status = get_unaligned_be16(&req->sample[1]); 448 status = status >> 3; 449 status &= 0x0fff; 450 } 451 452 kfree(req); 453 return status; 454 } 455 456 #if IS_ENABLED(CONFIG_HWMON) 457 458 #define SHOW(name, var, adjust) static ssize_t \ 459 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 460 { \ 461 struct ads7846 *ts = dev_get_drvdata(dev); \ 462 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 463 READ_12BIT_SER(var)); \ 464 if (v < 0) \ 465 return v; \ 466 return sprintf(buf, "%u\n", adjust(ts, v)); \ 467 } \ 468 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 469 470 471 /* Sysfs conventions report temperatures in millidegrees Celsius. 472 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 473 * accuracy scheme without calibration data. For now we won't try either; 474 * userspace sees raw sensor values, and must scale/calibrate appropriately. 475 */ 476 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 477 { 478 return v; 479 } 480 481 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 482 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 483 484 485 /* sysfs conventions report voltages in millivolts. We can convert voltages 486 * if we know vREF. userspace may need to scale vAUX to match the board's 487 * external resistors; we assume that vBATT only uses the internal ones. 488 */ 489 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 490 { 491 unsigned retval = v; 492 493 /* external resistors may scale vAUX into 0..vREF */ 494 retval *= ts->vref_mv; 495 retval = retval >> 12; 496 497 return retval; 498 } 499 500 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 501 { 502 unsigned retval = vaux_adjust(ts, v); 503 504 /* ads7846 has a resistor ladder to scale this signal down */ 505 if (ts->model == 7846) 506 retval *= 4; 507 508 return retval; 509 } 510 511 SHOW(in0_input, vaux, vaux_adjust) 512 SHOW(in1_input, vbatt, vbatt_adjust) 513 514 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 515 int index) 516 { 517 struct device *dev = kobj_to_dev(kobj); 518 struct ads7846 *ts = dev_get_drvdata(dev); 519 520 if (ts->model == 7843 && index < 2) /* in0, in1 */ 521 return 0; 522 if (ts->model == 7845 && index != 2) /* in0 */ 523 return 0; 524 525 return attr->mode; 526 } 527 528 static struct attribute *ads7846_attributes[] = { 529 &dev_attr_temp0.attr, /* 0 */ 530 &dev_attr_temp1.attr, /* 1 */ 531 &dev_attr_in0_input.attr, /* 2 */ 532 &dev_attr_in1_input.attr, /* 3 */ 533 NULL, 534 }; 535 536 static const struct attribute_group ads7846_attr_group = { 537 .attrs = ads7846_attributes, 538 .is_visible = ads7846_is_visible, 539 }; 540 __ATTRIBUTE_GROUPS(ads7846_attr); 541 542 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 543 { 544 /* hwmon sensors need a reference voltage */ 545 switch (ts->model) { 546 case 7846: 547 if (!ts->vref_mv) { 548 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 549 ts->vref_mv = 2500; 550 ts->use_internal = true; 551 } 552 break; 553 case 7845: 554 case 7843: 555 if (!ts->vref_mv) { 556 dev_warn(&spi->dev, 557 "external vREF for ADS%d not specified\n", 558 ts->model); 559 return 0; 560 } 561 break; 562 } 563 564 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 565 ts, ads7846_attr_groups); 566 567 return PTR_ERR_OR_ZERO(ts->hwmon); 568 } 569 570 static void ads784x_hwmon_unregister(struct spi_device *spi, 571 struct ads7846 *ts) 572 { 573 if (ts->hwmon) 574 hwmon_device_unregister(ts->hwmon); 575 } 576 577 #else 578 static inline int ads784x_hwmon_register(struct spi_device *spi, 579 struct ads7846 *ts) 580 { 581 return 0; 582 } 583 584 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 585 struct ads7846 *ts) 586 { 587 } 588 #endif 589 590 static ssize_t ads7846_pen_down_show(struct device *dev, 591 struct device_attribute *attr, char *buf) 592 { 593 struct ads7846 *ts = dev_get_drvdata(dev); 594 595 return sprintf(buf, "%u\n", ts->pendown); 596 } 597 598 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 599 600 static ssize_t ads7846_disable_show(struct device *dev, 601 struct device_attribute *attr, char *buf) 602 { 603 struct ads7846 *ts = dev_get_drvdata(dev); 604 605 return sprintf(buf, "%u\n", ts->disabled); 606 } 607 608 static ssize_t ads7846_disable_store(struct device *dev, 609 struct device_attribute *attr, 610 const char *buf, size_t count) 611 { 612 struct ads7846 *ts = dev_get_drvdata(dev); 613 unsigned int i; 614 int err; 615 616 err = kstrtouint(buf, 10, &i); 617 if (err) 618 return err; 619 620 if (i) 621 ads7846_disable(ts); 622 else 623 ads7846_enable(ts); 624 625 return count; 626 } 627 628 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 629 630 static struct attribute *ads784x_attributes[] = { 631 &dev_attr_pen_down.attr, 632 &dev_attr_disable.attr, 633 NULL, 634 }; 635 636 static const struct attribute_group ads784x_attr_group = { 637 .attrs = ads784x_attributes, 638 }; 639 640 /*--------------------------------------------------------------------------*/ 641 642 static void null_wait_for_sync(void) 643 { 644 } 645 646 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 647 { 648 struct ads7846 *ts = ads; 649 650 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 651 /* Start over collecting consistent readings. */ 652 ts->read_rep = 0; 653 /* 654 * Repeat it, if this was the first read or the read 655 * wasn't consistent enough. 656 */ 657 if (ts->read_cnt < ts->debounce_max) { 658 ts->last_read = *val; 659 ts->read_cnt++; 660 return ADS7846_FILTER_REPEAT; 661 } else { 662 /* 663 * Maximum number of debouncing reached and still 664 * not enough number of consistent readings. Abort 665 * the whole sample, repeat it in the next sampling 666 * period. 667 */ 668 ts->read_cnt = 0; 669 return ADS7846_FILTER_IGNORE; 670 } 671 } else { 672 if (++ts->read_rep > ts->debounce_rep) { 673 /* 674 * Got a good reading for this coordinate, 675 * go for the next one. 676 */ 677 ts->read_cnt = 0; 678 ts->read_rep = 0; 679 return ADS7846_FILTER_OK; 680 } else { 681 /* Read more values that are consistent. */ 682 ts->read_cnt++; 683 return ADS7846_FILTER_REPEAT; 684 } 685 } 686 } 687 688 static int ads7846_no_filter(void *ads, int data_idx, int *val) 689 { 690 return ADS7846_FILTER_OK; 691 } 692 693 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) 694 { 695 int value; 696 struct spi_transfer *t = 697 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 698 struct ads7846_buf *buf = t->rx_buf; 699 700 value = be16_to_cpup(&buf->data_be16); 701 702 /* enforce ADC output is 12 bits width */ 703 return (value >> 3) & 0xfff; 704 } 705 706 static void ads7846_update_value(struct spi_message *m, int val) 707 { 708 struct spi_transfer *t = 709 list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 710 struct ads7846_buf *buf = t->rx_buf; 711 712 buf->data = val; 713 } 714 715 static void ads7846_read_state(struct ads7846 *ts) 716 { 717 struct ads7846_packet *packet = ts->packet; 718 struct spi_message *m; 719 int msg_idx = 0; 720 int val; 721 int action; 722 int error; 723 724 while (msg_idx < ts->msg_count) { 725 726 ts->wait_for_sync(); 727 728 m = &ts->msg[msg_idx]; 729 error = spi_sync(ts->spi, m); 730 if (error) { 731 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 732 packet->tc.ignore = true; 733 return; 734 } 735 736 /* 737 * Last message is power down request, no need to convert 738 * or filter the value. 739 */ 740 if (msg_idx < ts->msg_count - 1) { 741 742 val = ads7846_get_value(ts, m); 743 744 action = ts->filter(ts->filter_data, msg_idx, &val); 745 switch (action) { 746 case ADS7846_FILTER_REPEAT: 747 continue; 748 749 case ADS7846_FILTER_IGNORE: 750 packet->tc.ignore = true; 751 msg_idx = ts->msg_count - 1; 752 continue; 753 754 case ADS7846_FILTER_OK: 755 ads7846_update_value(m, val); 756 packet->tc.ignore = false; 757 msg_idx++; 758 break; 759 760 default: 761 BUG(); 762 } 763 } else { 764 msg_idx++; 765 } 766 } 767 } 768 769 static void ads7846_report_state(struct ads7846 *ts) 770 { 771 struct ads7846_packet *packet = ts->packet; 772 unsigned int Rt; 773 u16 x, y, z1, z2; 774 775 /* 776 * ads7846_get_value() does in-place conversion (including byte swap) 777 * from on-the-wire format as part of debouncing to get stable 778 * readings. 779 */ 780 x = packet->tc.x.data; 781 y = packet->tc.y.data; 782 if (ts->model == 7845) { 783 z1 = 0; 784 z2 = 0; 785 } else { 786 z1 = packet->tc.z1.data; 787 z2 = packet->tc.z2.data; 788 } 789 790 /* range filtering */ 791 if (x == MAX_12BIT) 792 x = 0; 793 794 if (ts->model == 7843) { 795 Rt = ts->pressure_max / 2; 796 } else if (ts->model == 7845) { 797 if (get_pendown_state(ts)) 798 Rt = ts->pressure_max / 2; 799 else 800 Rt = 0; 801 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 802 } else if (likely(x && z1)) { 803 /* compute touch pressure resistance using equation #2 */ 804 Rt = z2; 805 Rt -= z1; 806 Rt *= ts->x_plate_ohms; 807 Rt = DIV_ROUND_CLOSEST(Rt, 16); 808 Rt *= x; 809 Rt /= z1; 810 Rt = DIV_ROUND_CLOSEST(Rt, 256); 811 } else { 812 Rt = 0; 813 } 814 815 /* 816 * Sample found inconsistent by debouncing or pressure is beyond 817 * the maximum. Don't report it to user space, repeat at least 818 * once more the measurement 819 */ 820 if (packet->tc.ignore || Rt > ts->pressure_max) { 821 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 822 packet->tc.ignore, Rt); 823 return; 824 } 825 826 /* 827 * Maybe check the pendown state before reporting. This discards 828 * false readings when the pen is lifted. 829 */ 830 if (ts->penirq_recheck_delay_usecs) { 831 udelay(ts->penirq_recheck_delay_usecs); 832 if (!get_pendown_state(ts)) 833 Rt = 0; 834 } 835 836 /* 837 * NOTE: We can't rely on the pressure to determine the pen down 838 * state, even this controller has a pressure sensor. The pressure 839 * value can fluctuate for quite a while after lifting the pen and 840 * in some cases may not even settle at the expected value. 841 * 842 * The only safe way to check for the pen up condition is in the 843 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 844 */ 845 if (Rt) { 846 struct input_dev *input = ts->input; 847 848 if (!ts->pendown) { 849 input_report_key(input, BTN_TOUCH, 1); 850 ts->pendown = true; 851 dev_vdbg(&ts->spi->dev, "DOWN\n"); 852 } 853 854 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 855 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 856 857 input_sync(input); 858 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 859 } 860 } 861 862 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 863 { 864 struct ads7846 *ts = handle; 865 866 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 867 } 868 869 870 static irqreturn_t ads7846_irq(int irq, void *handle) 871 { 872 struct ads7846 *ts = handle; 873 874 /* Start with a small delay before checking pendown state */ 875 msleep(TS_POLL_DELAY); 876 877 while (!ts->stopped && get_pendown_state(ts)) { 878 879 /* pen is down, continue with the measurement */ 880 ads7846_read_state(ts); 881 882 if (!ts->stopped) 883 ads7846_report_state(ts); 884 885 wait_event_timeout(ts->wait, ts->stopped, 886 msecs_to_jiffies(TS_POLL_PERIOD)); 887 } 888 889 if (ts->pendown && !ts->stopped) 890 ads7846_report_pen_up(ts); 891 892 return IRQ_HANDLED; 893 } 894 895 static int __maybe_unused ads7846_suspend(struct device *dev) 896 { 897 struct ads7846 *ts = dev_get_drvdata(dev); 898 899 mutex_lock(&ts->lock); 900 901 if (!ts->suspended) { 902 903 if (!ts->disabled) 904 __ads7846_disable(ts); 905 906 if (device_may_wakeup(&ts->spi->dev)) 907 enable_irq_wake(ts->spi->irq); 908 909 ts->suspended = true; 910 } 911 912 mutex_unlock(&ts->lock); 913 914 return 0; 915 } 916 917 static int __maybe_unused ads7846_resume(struct device *dev) 918 { 919 struct ads7846 *ts = dev_get_drvdata(dev); 920 921 mutex_lock(&ts->lock); 922 923 if (ts->suspended) { 924 925 ts->suspended = false; 926 927 if (device_may_wakeup(&ts->spi->dev)) 928 disable_irq_wake(ts->spi->irq); 929 930 if (!ts->disabled) 931 __ads7846_enable(ts); 932 } 933 934 mutex_unlock(&ts->lock); 935 936 return 0; 937 } 938 939 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 940 941 static int ads7846_setup_pendown(struct spi_device *spi, 942 struct ads7846 *ts, 943 const struct ads7846_platform_data *pdata) 944 { 945 int err; 946 947 /* 948 * REVISIT when the irq can be triggered active-low, or if for some 949 * reason the touchscreen isn't hooked up, we don't need to access 950 * the pendown state. 951 */ 952 953 if (pdata->get_pendown_state) { 954 ts->get_pendown_state = pdata->get_pendown_state; 955 } else if (gpio_is_valid(pdata->gpio_pendown)) { 956 957 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 958 "ads7846_pendown"); 959 if (err) { 960 dev_err(&spi->dev, 961 "failed to request/setup pendown GPIO%d: %d\n", 962 pdata->gpio_pendown, err); 963 return err; 964 } 965 966 ts->gpio_pendown = pdata->gpio_pendown; 967 968 if (pdata->gpio_pendown_debounce) 969 gpio_set_debounce(pdata->gpio_pendown, 970 pdata->gpio_pendown_debounce); 971 } else { 972 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 973 return -EINVAL; 974 } 975 976 return 0; 977 } 978 979 /* 980 * Set up the transfers to read touchscreen state; this assumes we 981 * use formula #2 for pressure, not #3. 982 */ 983 static void ads7846_setup_spi_msg(struct ads7846 *ts, 984 const struct ads7846_platform_data *pdata) 985 { 986 struct spi_message *m = &ts->msg[0]; 987 struct spi_transfer *x = ts->xfer; 988 struct ads7846_packet *packet = ts->packet; 989 int vref = pdata->keep_vref_on; 990 991 if (ts->model == 7873) { 992 /* 993 * The AD7873 is almost identical to the ADS7846 994 * keep VREF off during differential/ratiometric 995 * conversion modes. 996 */ 997 ts->model = 7846; 998 vref = 0; 999 } 1000 1001 ts->msg_count = 1; 1002 spi_message_init(m); 1003 m->context = ts; 1004 1005 packet->read_y_cmd.cmd = READ_Y(vref); 1006 x->tx_buf = &packet->read_y_cmd; 1007 x->rx_buf = &packet->tc.y; 1008 x->len = 3; 1009 spi_message_add_tail(x, m); 1010 1011 /* 1012 * The first sample after switching drivers can be low quality; 1013 * optionally discard it, using a second one after the signals 1014 * have had enough time to stabilize. 1015 */ 1016 if (pdata->settle_delay_usecs) { 1017 x->delay.value = pdata->settle_delay_usecs; 1018 x->delay.unit = SPI_DELAY_UNIT_USECS; 1019 x++; 1020 1021 x->tx_buf = &packet->read_y_cmd; 1022 x->rx_buf = &packet->tc.y; 1023 x->len = 3; 1024 spi_message_add_tail(x, m); 1025 } 1026 1027 ts->msg_count++; 1028 m++; 1029 spi_message_init(m); 1030 m->context = ts; 1031 1032 /* turn y- off, x+ on, then leave in lowpower */ 1033 x++; 1034 packet->read_x_cmd.cmd = READ_X(vref); 1035 x->tx_buf = &packet->read_x_cmd; 1036 x->rx_buf = &packet->tc.x; 1037 x->len = 3; 1038 spi_message_add_tail(x, m); 1039 1040 /* ... maybe discard first sample ... */ 1041 if (pdata->settle_delay_usecs) { 1042 x->delay.value = pdata->settle_delay_usecs; 1043 x->delay.unit = SPI_DELAY_UNIT_USECS; 1044 1045 x++; 1046 x->tx_buf = &packet->read_x_cmd; 1047 x->rx_buf = &packet->tc.x; 1048 x->len = 3; 1049 spi_message_add_tail(x, m); 1050 } 1051 1052 /* turn y+ off, x- on; we'll use formula #2 */ 1053 if (ts->model == 7846) { 1054 ts->msg_count++; 1055 m++; 1056 spi_message_init(m); 1057 m->context = ts; 1058 1059 x++; 1060 packet->read_z1_cmd.cmd = READ_Z1(vref); 1061 x->tx_buf = &packet->read_z1_cmd; 1062 x->rx_buf = &packet->tc.z1; 1063 x->len = 3; 1064 spi_message_add_tail(x, m); 1065 1066 /* ... maybe discard first sample ... */ 1067 if (pdata->settle_delay_usecs) { 1068 x->delay.value = pdata->settle_delay_usecs; 1069 x->delay.unit = SPI_DELAY_UNIT_USECS; 1070 1071 x++; 1072 x->tx_buf = &packet->read_z1_cmd; 1073 x->rx_buf = &packet->tc.z1; 1074 x->len = 3; 1075 spi_message_add_tail(x, m); 1076 } 1077 1078 ts->msg_count++; 1079 m++; 1080 spi_message_init(m); 1081 m->context = ts; 1082 1083 x++; 1084 packet->read_z2_cmd.cmd = READ_Z2(vref); 1085 x->tx_buf = &packet->read_z2_cmd; 1086 x->rx_buf = &packet->tc.z2; 1087 x->len = 3; 1088 spi_message_add_tail(x, m); 1089 1090 /* ... maybe discard first sample ... */ 1091 if (pdata->settle_delay_usecs) { 1092 x->delay.value = pdata->settle_delay_usecs; 1093 x->delay.unit = SPI_DELAY_UNIT_USECS; 1094 1095 x++; 1096 x->tx_buf = &packet->read_z2_cmd; 1097 x->rx_buf = &packet->tc.z2; 1098 x->len = 3; 1099 spi_message_add_tail(x, m); 1100 } 1101 } 1102 1103 /* power down */ 1104 ts->msg_count++; 1105 m++; 1106 spi_message_init(m); 1107 m->context = ts; 1108 1109 x++; 1110 packet->pwrdown_cmd.cmd = PWRDOWN; 1111 x->tx_buf = &packet->pwrdown_cmd; 1112 x->len = 3; 1113 1114 CS_CHANGE(*x); 1115 spi_message_add_tail(x, m); 1116 } 1117 1118 #ifdef CONFIG_OF 1119 static const struct of_device_id ads7846_dt_ids[] = { 1120 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1121 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1122 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1123 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1124 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1125 { } 1126 }; 1127 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1128 1129 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1130 { 1131 struct ads7846_platform_data *pdata; 1132 struct device_node *node = dev->of_node; 1133 const struct of_device_id *match; 1134 u32 value; 1135 1136 if (!node) { 1137 dev_err(dev, "Device does not have associated DT data\n"); 1138 return ERR_PTR(-EINVAL); 1139 } 1140 1141 match = of_match_device(ads7846_dt_ids, dev); 1142 if (!match) { 1143 dev_err(dev, "Unknown device model\n"); 1144 return ERR_PTR(-EINVAL); 1145 } 1146 1147 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1148 if (!pdata) 1149 return ERR_PTR(-ENOMEM); 1150 1151 pdata->model = (unsigned long)match->data; 1152 1153 of_property_read_u16(node, "ti,vref-delay-usecs", 1154 &pdata->vref_delay_usecs); 1155 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1156 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1157 1158 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1159 1160 of_property_read_u16(node, "ti,settle-delay-usec", 1161 &pdata->settle_delay_usecs); 1162 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1163 &pdata->penirq_recheck_delay_usecs); 1164 1165 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1166 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1167 1168 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1169 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1170 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1171 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1172 1173 /* 1174 * touchscreen-max-pressure gets parsed during 1175 * touchscreen_parse_properties() 1176 */ 1177 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1178 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1179 pdata->pressure_min = (u16) value; 1180 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1181 1182 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1183 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1184 pdata->debounce_max = (u16) value; 1185 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1186 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1187 1188 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1189 &pdata->gpio_pendown_debounce); 1190 1191 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1192 of_property_read_bool(node, "linux,wakeup"); 1193 1194 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1195 1196 return pdata; 1197 } 1198 #else 1199 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1200 { 1201 dev_err(dev, "no platform data defined\n"); 1202 return ERR_PTR(-EINVAL); 1203 } 1204 #endif 1205 1206 static int ads7846_probe(struct spi_device *spi) 1207 { 1208 const struct ads7846_platform_data *pdata; 1209 struct ads7846 *ts; 1210 struct ads7846_packet *packet; 1211 struct input_dev *input_dev; 1212 unsigned long irq_flags; 1213 int err; 1214 1215 if (!spi->irq) { 1216 dev_dbg(&spi->dev, "no IRQ?\n"); 1217 return -EINVAL; 1218 } 1219 1220 /* don't exceed max specified sample rate */ 1221 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1222 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1223 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1224 return -EINVAL; 1225 } 1226 1227 /* 1228 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1229 * that even if the hardware can do that, the SPI controller driver 1230 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1231 */ 1232 spi->bits_per_word = 8; 1233 spi->mode = SPI_MODE_0; 1234 err = spi_setup(spi); 1235 if (err < 0) 1236 return err; 1237 1238 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1239 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1240 input_dev = input_allocate_device(); 1241 if (!ts || !packet || !input_dev) { 1242 err = -ENOMEM; 1243 goto err_free_mem; 1244 } 1245 1246 spi_set_drvdata(spi, ts); 1247 1248 ts->packet = packet; 1249 ts->spi = spi; 1250 ts->input = input_dev; 1251 1252 mutex_init(&ts->lock); 1253 init_waitqueue_head(&ts->wait); 1254 1255 pdata = dev_get_platdata(&spi->dev); 1256 if (!pdata) { 1257 pdata = ads7846_probe_dt(&spi->dev); 1258 if (IS_ERR(pdata)) { 1259 err = PTR_ERR(pdata); 1260 goto err_free_mem; 1261 } 1262 } 1263 1264 ts->model = pdata->model ? : 7846; 1265 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1266 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1267 ts->vref_mv = pdata->vref_mv; 1268 1269 if (pdata->filter != NULL) { 1270 if (pdata->filter_init != NULL) { 1271 err = pdata->filter_init(pdata, &ts->filter_data); 1272 if (err < 0) 1273 goto err_free_mem; 1274 } 1275 ts->filter = pdata->filter; 1276 ts->filter_cleanup = pdata->filter_cleanup; 1277 } else if (pdata->debounce_max) { 1278 ts->debounce_max = pdata->debounce_max; 1279 if (ts->debounce_max < 2) 1280 ts->debounce_max = 2; 1281 ts->debounce_tol = pdata->debounce_tol; 1282 ts->debounce_rep = pdata->debounce_rep; 1283 ts->filter = ads7846_debounce_filter; 1284 ts->filter_data = ts; 1285 } else { 1286 ts->filter = ads7846_no_filter; 1287 } 1288 1289 err = ads7846_setup_pendown(spi, ts, pdata); 1290 if (err) 1291 goto err_cleanup_filter; 1292 1293 if (pdata->penirq_recheck_delay_usecs) 1294 ts->penirq_recheck_delay_usecs = 1295 pdata->penirq_recheck_delay_usecs; 1296 1297 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1298 1299 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1300 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1301 1302 input_dev->name = ts->name; 1303 input_dev->phys = ts->phys; 1304 input_dev->dev.parent = &spi->dev; 1305 1306 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1307 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1308 input_set_abs_params(input_dev, ABS_X, 1309 pdata->x_min ? : 0, 1310 pdata->x_max ? : MAX_12BIT, 1311 0, 0); 1312 input_set_abs_params(input_dev, ABS_Y, 1313 pdata->y_min ? : 0, 1314 pdata->y_max ? : MAX_12BIT, 1315 0, 0); 1316 input_set_abs_params(input_dev, ABS_PRESSURE, 1317 pdata->pressure_min, pdata->pressure_max, 0, 0); 1318 1319 /* 1320 * Parse common framework properties. Must be done here to ensure the 1321 * correct behaviour in case of using the legacy vendor bindings. The 1322 * general binding value overrides the vendor specific one. 1323 */ 1324 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1325 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1326 1327 /* 1328 * Check if legacy ti,swap-xy binding is used instead of 1329 * touchscreen-swapped-x-y 1330 */ 1331 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1332 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1333 ts->core_prop.swap_x_y = true; 1334 } 1335 1336 ads7846_setup_spi_msg(ts, pdata); 1337 1338 ts->reg = regulator_get(&spi->dev, "vcc"); 1339 if (IS_ERR(ts->reg)) { 1340 err = PTR_ERR(ts->reg); 1341 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1342 goto err_free_gpio; 1343 } 1344 1345 err = regulator_enable(ts->reg); 1346 if (err) { 1347 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1348 goto err_put_regulator; 1349 } 1350 1351 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1352 irq_flags |= IRQF_ONESHOT; 1353 1354 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1355 irq_flags, spi->dev.driver->name, ts); 1356 if (err && !pdata->irq_flags) { 1357 dev_info(&spi->dev, 1358 "trying pin change workaround on irq %d\n", spi->irq); 1359 irq_flags |= IRQF_TRIGGER_RISING; 1360 err = request_threaded_irq(spi->irq, 1361 ads7846_hard_irq, ads7846_irq, 1362 irq_flags, spi->dev.driver->name, ts); 1363 } 1364 1365 if (err) { 1366 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1367 goto err_disable_regulator; 1368 } 1369 1370 err = ads784x_hwmon_register(spi, ts); 1371 if (err) 1372 goto err_free_irq; 1373 1374 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1375 1376 /* 1377 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1378 * the touchscreen, in case it's not connected. 1379 */ 1380 if (ts->model == 7845) 1381 ads7845_read12_ser(&spi->dev, PWRDOWN); 1382 else 1383 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1384 1385 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1386 if (err) 1387 goto err_remove_hwmon; 1388 1389 err = input_register_device(input_dev); 1390 if (err) 1391 goto err_remove_attr_group; 1392 1393 device_init_wakeup(&spi->dev, pdata->wakeup); 1394 1395 /* 1396 * If device does not carry platform data we must have allocated it 1397 * when parsing DT data. 1398 */ 1399 if (!dev_get_platdata(&spi->dev)) 1400 devm_kfree(&spi->dev, (void *)pdata); 1401 1402 return 0; 1403 1404 err_remove_attr_group: 1405 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1406 err_remove_hwmon: 1407 ads784x_hwmon_unregister(spi, ts); 1408 err_free_irq: 1409 free_irq(spi->irq, ts); 1410 err_disable_regulator: 1411 regulator_disable(ts->reg); 1412 err_put_regulator: 1413 regulator_put(ts->reg); 1414 err_free_gpio: 1415 if (!ts->get_pendown_state) 1416 gpio_free(ts->gpio_pendown); 1417 err_cleanup_filter: 1418 if (ts->filter_cleanup) 1419 ts->filter_cleanup(ts->filter_data); 1420 err_free_mem: 1421 input_free_device(input_dev); 1422 kfree(packet); 1423 kfree(ts); 1424 return err; 1425 } 1426 1427 static int ads7846_remove(struct spi_device *spi) 1428 { 1429 struct ads7846 *ts = spi_get_drvdata(spi); 1430 1431 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1432 1433 ads7846_disable(ts); 1434 free_irq(ts->spi->irq, ts); 1435 1436 input_unregister_device(ts->input); 1437 1438 ads784x_hwmon_unregister(spi, ts); 1439 1440 regulator_put(ts->reg); 1441 1442 if (!ts->get_pendown_state) { 1443 /* 1444 * If we are not using specialized pendown method we must 1445 * have been relying on gpio we set up ourselves. 1446 */ 1447 gpio_free(ts->gpio_pendown); 1448 } 1449 1450 if (ts->filter_cleanup) 1451 ts->filter_cleanup(ts->filter_data); 1452 1453 kfree(ts->packet); 1454 kfree(ts); 1455 1456 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1457 1458 return 0; 1459 } 1460 1461 static struct spi_driver ads7846_driver = { 1462 .driver = { 1463 .name = "ads7846", 1464 .pm = &ads7846_pm, 1465 .of_match_table = of_match_ptr(ads7846_dt_ids), 1466 }, 1467 .probe = ads7846_probe, 1468 .remove = ads7846_remove, 1469 }; 1470 1471 module_spi_driver(ads7846_driver); 1472 1473 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1474 MODULE_LICENSE("GPL"); 1475 MODULE_ALIAS("spi:ads7846"); 1476