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/unaligned.h> 36 37 /* 38 * This code has been heavily tested on a Nokia 770, and lightly 39 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). 40 * TSC2046 is just newer ads7846 silicon. 41 * Support for ads7843 tested on Atmel at91sam926x-EK. 42 * Support for ads7845 has only been stubbed in. 43 * Support for Analog Devices AD7873 and AD7843 tested. 44 * 45 * IRQ handling needs a workaround because of a shortcoming in handling 46 * edge triggered IRQs on some platforms like the OMAP1/2. These 47 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 48 * have to maintain our own SW IRQ disabled status. This should be 49 * removed as soon as the affected platform's IRQ handling is fixed. 50 * 51 * App note sbaa036 talks in more detail about accurate sampling... 52 * that ought to help in situations like LCDs inducing noise (which 53 * can also be helped by using synch signals) and more generally. 54 * This driver tries to utilize the measures described in the app 55 * note. The strength of filtering can be set in the board-* specific 56 * files. 57 */ 58 59 #define TS_POLL_DELAY 1 /* ms delay before the first sample */ 60 #define TS_POLL_PERIOD 5 /* ms delay between samples */ 61 62 /* this driver doesn't aim at the peak continuous sample rate */ 63 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 64 65 struct ads7846_buf { 66 u8 cmd; 67 __be16 data; 68 } __packed; 69 70 struct ads7846_buf_layout { 71 unsigned int offset; 72 unsigned int count; 73 unsigned int skip; 74 }; 75 76 /* 77 * We allocate this separately to avoid cache line sharing issues when 78 * driver is used with DMA-based SPI controllers (like atmel_spi) on 79 * systems where main memory is not DMA-coherent (most non-x86 boards). 80 */ 81 struct ads7846_packet { 82 unsigned int count; 83 unsigned int count_skip; 84 unsigned int cmds; 85 unsigned int last_cmd_idx; 86 struct ads7846_buf_layout l[5]; 87 struct ads7846_buf *rx; 88 struct ads7846_buf *tx; 89 90 struct ads7846_buf pwrdown_cmd; 91 92 bool ignore; 93 u16 x, y, z1, z2; 94 }; 95 96 struct ads7846 { 97 struct input_dev *input; 98 char phys[32]; 99 char name[32]; 100 101 struct spi_device *spi; 102 struct regulator *reg; 103 104 #if IS_ENABLED(CONFIG_HWMON) 105 struct device *hwmon; 106 #endif 107 108 u16 model; 109 u16 vref_mv; 110 u16 vref_delay_usecs; 111 u16 x_plate_ohms; 112 u16 pressure_max; 113 114 bool swap_xy; 115 bool use_internal; 116 117 struct ads7846_packet *packet; 118 119 struct spi_transfer xfer[18]; 120 struct spi_message msg[5]; 121 int msg_count; 122 wait_queue_head_t wait; 123 124 bool pendown; 125 126 int read_cnt; 127 int read_rep; 128 int last_read; 129 130 u16 debounce_max; 131 u16 debounce_tol; 132 u16 debounce_rep; 133 134 u16 penirq_recheck_delay_usecs; 135 136 struct touchscreen_properties core_prop; 137 138 struct mutex lock; 139 bool stopped; /* P: lock */ 140 bool disabled; /* P: lock */ 141 bool suspended; /* P: lock */ 142 143 int (*filter)(void *data, int data_idx, int *val); 144 void *filter_data; 145 void (*filter_cleanup)(void *data); 146 int (*get_pendown_state)(void); 147 int gpio_pendown; 148 149 void (*wait_for_sync)(void); 150 }; 151 152 /* leave chip selected when we're done, for quicker re-select? */ 153 #if 0 154 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 155 #else 156 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 157 #endif 158 159 /*--------------------------------------------------------------------------*/ 160 161 /* The ADS7846 has touchscreen and other sensors. 162 * Earlier ads784x chips are somewhat compatible. 163 */ 164 #define ADS_START (1 << 7) 165 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 166 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 167 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 168 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 169 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 170 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 171 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 172 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 173 #define ADS_8_BIT (1 << 3) 174 #define ADS_12_BIT (0 << 3) 175 #define ADS_SER (1 << 2) /* non-differential */ 176 #define ADS_DFR (0 << 2) /* differential */ 177 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */ 178 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 179 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 180 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 181 182 #define MAX_12BIT ((1<<12)-1) 183 184 /* leave ADC powered up (disables penirq) between differential samples */ 185 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \ 186 | ADS_12_BIT | ADS_DFR | \ 187 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0)) 188 189 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref)) 190 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref)) 191 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref)) 192 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref)) 193 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */ 194 195 /* single-ended samples need to first power up reference voltage; 196 * we leave both ADC and VREF powered 197 */ 198 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 199 | ADS_12_BIT | ADS_SER) 200 201 #define REF_ON (READ_12BIT_DFR(x, 1, 1)) 202 #define REF_OFF (READ_12BIT_DFR(y, 0, 0)) 203 204 /* Order commands in the most optimal way to reduce Vref switching and 205 * settling time: 206 * Measure: X; Vref: X+, X-; IN: Y+ 207 * Measure: Y; Vref: Y+, Y-; IN: X+ 208 * Measure: Z1; Vref: Y+, X-; IN: X+ 209 * Measure: Z2; Vref: Y+, X-; IN: Y- 210 */ 211 enum ads7846_cmds { 212 ADS7846_X, 213 ADS7846_Y, 214 ADS7846_Z1, 215 ADS7846_Z2, 216 ADS7846_PWDOWN, 217 }; 218 219 static int get_pendown_state(struct ads7846 *ts) 220 { 221 if (ts->get_pendown_state) 222 return ts->get_pendown_state(); 223 224 return !gpio_get_value(ts->gpio_pendown); 225 } 226 227 static void ads7846_report_pen_up(struct ads7846 *ts) 228 { 229 struct input_dev *input = ts->input; 230 231 input_report_key(input, BTN_TOUCH, 0); 232 input_report_abs(input, ABS_PRESSURE, 0); 233 input_sync(input); 234 235 ts->pendown = false; 236 dev_vdbg(&ts->spi->dev, "UP\n"); 237 } 238 239 /* Must be called with ts->lock held */ 240 static void ads7846_stop(struct ads7846 *ts) 241 { 242 if (!ts->disabled && !ts->suspended) { 243 /* Signal IRQ thread to stop polling and disable the handler. */ 244 ts->stopped = true; 245 mb(); 246 wake_up(&ts->wait); 247 disable_irq(ts->spi->irq); 248 } 249 } 250 251 /* Must be called with ts->lock held */ 252 static void ads7846_restart(struct ads7846 *ts) 253 { 254 if (!ts->disabled && !ts->suspended) { 255 /* Check if pen was released since last stop */ 256 if (ts->pendown && !get_pendown_state(ts)) 257 ads7846_report_pen_up(ts); 258 259 /* Tell IRQ thread that it may poll the device. */ 260 ts->stopped = false; 261 mb(); 262 enable_irq(ts->spi->irq); 263 } 264 } 265 266 /* Must be called with ts->lock held */ 267 static void __ads7846_disable(struct ads7846 *ts) 268 { 269 ads7846_stop(ts); 270 regulator_disable(ts->reg); 271 272 /* 273 * We know the chip's in low power mode since we always 274 * leave it that way after every request 275 */ 276 } 277 278 /* Must be called with ts->lock held */ 279 static void __ads7846_enable(struct ads7846 *ts) 280 { 281 int error; 282 283 error = regulator_enable(ts->reg); 284 if (error != 0) 285 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error); 286 287 ads7846_restart(ts); 288 } 289 290 static void ads7846_disable(struct ads7846 *ts) 291 { 292 mutex_lock(&ts->lock); 293 294 if (!ts->disabled) { 295 296 if (!ts->suspended) 297 __ads7846_disable(ts); 298 299 ts->disabled = true; 300 } 301 302 mutex_unlock(&ts->lock); 303 } 304 305 static void ads7846_enable(struct ads7846 *ts) 306 { 307 mutex_lock(&ts->lock); 308 309 if (ts->disabled) { 310 311 ts->disabled = false; 312 313 if (!ts->suspended) 314 __ads7846_enable(ts); 315 } 316 317 mutex_unlock(&ts->lock); 318 } 319 320 /*--------------------------------------------------------------------------*/ 321 322 /* 323 * Non-touchscreen sensors only use single-ended conversions. 324 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF; 325 * ads7846 lets that pin be unconnected, to use internal vREF. 326 */ 327 328 struct ser_req { 329 u8 ref_on; 330 u8 command; 331 u8 ref_off; 332 u16 scratch; 333 struct spi_message msg; 334 struct spi_transfer xfer[6]; 335 /* 336 * DMA (thus cache coherency maintenance) requires the 337 * transfer buffers to live in their own cache lines. 338 */ 339 __be16 sample ____cacheline_aligned; 340 }; 341 342 struct ads7845_ser_req { 343 u8 command[3]; 344 struct spi_message msg; 345 struct spi_transfer xfer[2]; 346 /* 347 * DMA (thus cache coherency maintenance) requires the 348 * transfer buffers to live in their own cache lines. 349 */ 350 u8 sample[3] ____cacheline_aligned; 351 }; 352 353 static int ads7846_read12_ser(struct device *dev, unsigned command) 354 { 355 struct spi_device *spi = to_spi_device(dev); 356 struct ads7846 *ts = dev_get_drvdata(dev); 357 struct ser_req *req; 358 int status; 359 360 req = kzalloc(sizeof *req, GFP_KERNEL); 361 if (!req) 362 return -ENOMEM; 363 364 spi_message_init(&req->msg); 365 366 /* maybe turn on internal vREF, and let it settle */ 367 if (ts->use_internal) { 368 req->ref_on = REF_ON; 369 req->xfer[0].tx_buf = &req->ref_on; 370 req->xfer[0].len = 1; 371 spi_message_add_tail(&req->xfer[0], &req->msg); 372 373 req->xfer[1].rx_buf = &req->scratch; 374 req->xfer[1].len = 2; 375 376 /* for 1uF, settle for 800 usec; no cap, 100 usec. */ 377 req->xfer[1].delay.value = ts->vref_delay_usecs; 378 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 379 spi_message_add_tail(&req->xfer[1], &req->msg); 380 381 /* Enable reference voltage */ 382 command |= ADS_PD10_REF_ON; 383 } 384 385 /* Enable ADC in every case */ 386 command |= ADS_PD10_ADC_ON; 387 388 /* take sample */ 389 req->command = (u8) command; 390 req->xfer[2].tx_buf = &req->command; 391 req->xfer[2].len = 1; 392 spi_message_add_tail(&req->xfer[2], &req->msg); 393 394 req->xfer[3].rx_buf = &req->sample; 395 req->xfer[3].len = 2; 396 spi_message_add_tail(&req->xfer[3], &req->msg); 397 398 /* REVISIT: take a few more samples, and compare ... */ 399 400 /* converter in low power mode & enable PENIRQ */ 401 req->ref_off = PWRDOWN; 402 req->xfer[4].tx_buf = &req->ref_off; 403 req->xfer[4].len = 1; 404 spi_message_add_tail(&req->xfer[4], &req->msg); 405 406 req->xfer[5].rx_buf = &req->scratch; 407 req->xfer[5].len = 2; 408 CS_CHANGE(req->xfer[5]); 409 spi_message_add_tail(&req->xfer[5], &req->msg); 410 411 mutex_lock(&ts->lock); 412 ads7846_stop(ts); 413 status = spi_sync(spi, &req->msg); 414 ads7846_restart(ts); 415 mutex_unlock(&ts->lock); 416 417 if (status == 0) { 418 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 419 status = be16_to_cpu(req->sample); 420 status = status >> 3; 421 status &= 0x0fff; 422 } 423 424 kfree(req); 425 return status; 426 } 427 428 static int ads7845_read12_ser(struct device *dev, unsigned command) 429 { 430 struct spi_device *spi = to_spi_device(dev); 431 struct ads7846 *ts = dev_get_drvdata(dev); 432 struct ads7845_ser_req *req; 433 int status; 434 435 req = kzalloc(sizeof *req, GFP_KERNEL); 436 if (!req) 437 return -ENOMEM; 438 439 spi_message_init(&req->msg); 440 441 req->command[0] = (u8) command; 442 req->xfer[0].tx_buf = req->command; 443 req->xfer[0].rx_buf = req->sample; 444 req->xfer[0].len = 3; 445 spi_message_add_tail(&req->xfer[0], &req->msg); 446 447 mutex_lock(&ts->lock); 448 ads7846_stop(ts); 449 status = spi_sync(spi, &req->msg); 450 ads7846_restart(ts); 451 mutex_unlock(&ts->lock); 452 453 if (status == 0) { 454 /* BE12 value, then padding */ 455 status = get_unaligned_be16(&req->sample[1]); 456 status = status >> 3; 457 status &= 0x0fff; 458 } 459 460 kfree(req); 461 return status; 462 } 463 464 #if IS_ENABLED(CONFIG_HWMON) 465 466 #define SHOW(name, var, adjust) static ssize_t \ 467 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 468 { \ 469 struct ads7846 *ts = dev_get_drvdata(dev); \ 470 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \ 471 READ_12BIT_SER(var)); \ 472 if (v < 0) \ 473 return v; \ 474 return sprintf(buf, "%u\n", adjust(ts, v)); \ 475 } \ 476 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 477 478 479 /* Sysfs conventions report temperatures in millidegrees Celsius. 480 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high 481 * accuracy scheme without calibration data. For now we won't try either; 482 * userspace sees raw sensor values, and must scale/calibrate appropriately. 483 */ 484 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v) 485 { 486 return v; 487 } 488 489 SHOW(temp0, temp0, null_adjust) /* temp1_input */ 490 SHOW(temp1, temp1, null_adjust) /* temp2_input */ 491 492 493 /* sysfs conventions report voltages in millivolts. We can convert voltages 494 * if we know vREF. userspace may need to scale vAUX to match the board's 495 * external resistors; we assume that vBATT only uses the internal ones. 496 */ 497 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v) 498 { 499 unsigned retval = v; 500 501 /* external resistors may scale vAUX into 0..vREF */ 502 retval *= ts->vref_mv; 503 retval = retval >> 12; 504 505 return retval; 506 } 507 508 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v) 509 { 510 unsigned retval = vaux_adjust(ts, v); 511 512 /* ads7846 has a resistor ladder to scale this signal down */ 513 if (ts->model == 7846) 514 retval *= 4; 515 516 return retval; 517 } 518 519 SHOW(in0_input, vaux, vaux_adjust) 520 SHOW(in1_input, vbatt, vbatt_adjust) 521 522 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr, 523 int index) 524 { 525 struct device *dev = kobj_to_dev(kobj); 526 struct ads7846 *ts = dev_get_drvdata(dev); 527 528 if (ts->model == 7843 && index < 2) /* in0, in1 */ 529 return 0; 530 if (ts->model == 7845 && index != 2) /* in0 */ 531 return 0; 532 533 return attr->mode; 534 } 535 536 static struct attribute *ads7846_attributes[] = { 537 &dev_attr_temp0.attr, /* 0 */ 538 &dev_attr_temp1.attr, /* 1 */ 539 &dev_attr_in0_input.attr, /* 2 */ 540 &dev_attr_in1_input.attr, /* 3 */ 541 NULL, 542 }; 543 544 static const struct attribute_group ads7846_attr_group = { 545 .attrs = ads7846_attributes, 546 .is_visible = ads7846_is_visible, 547 }; 548 __ATTRIBUTE_GROUPS(ads7846_attr); 549 550 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) 551 { 552 /* hwmon sensors need a reference voltage */ 553 switch (ts->model) { 554 case 7846: 555 if (!ts->vref_mv) { 556 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); 557 ts->vref_mv = 2500; 558 ts->use_internal = true; 559 } 560 break; 561 case 7845: 562 case 7843: 563 if (!ts->vref_mv) { 564 dev_warn(&spi->dev, 565 "external vREF for ADS%d not specified\n", 566 ts->model); 567 return 0; 568 } 569 break; 570 } 571 572 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias, 573 ts, ads7846_attr_groups); 574 575 return PTR_ERR_OR_ZERO(ts->hwmon); 576 } 577 578 static void ads784x_hwmon_unregister(struct spi_device *spi, 579 struct ads7846 *ts) 580 { 581 if (ts->hwmon) 582 hwmon_device_unregister(ts->hwmon); 583 } 584 585 #else 586 static inline int ads784x_hwmon_register(struct spi_device *spi, 587 struct ads7846 *ts) 588 { 589 return 0; 590 } 591 592 static inline void ads784x_hwmon_unregister(struct spi_device *spi, 593 struct ads7846 *ts) 594 { 595 } 596 #endif 597 598 static ssize_t ads7846_pen_down_show(struct device *dev, 599 struct device_attribute *attr, char *buf) 600 { 601 struct ads7846 *ts = dev_get_drvdata(dev); 602 603 return sprintf(buf, "%u\n", ts->pendown); 604 } 605 606 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 607 608 static ssize_t ads7846_disable_show(struct device *dev, 609 struct device_attribute *attr, char *buf) 610 { 611 struct ads7846 *ts = dev_get_drvdata(dev); 612 613 return sprintf(buf, "%u\n", ts->disabled); 614 } 615 616 static ssize_t ads7846_disable_store(struct device *dev, 617 struct device_attribute *attr, 618 const char *buf, size_t count) 619 { 620 struct ads7846 *ts = dev_get_drvdata(dev); 621 unsigned int i; 622 int err; 623 624 err = kstrtouint(buf, 10, &i); 625 if (err) 626 return err; 627 628 if (i) 629 ads7846_disable(ts); 630 else 631 ads7846_enable(ts); 632 633 return count; 634 } 635 636 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 637 638 static struct attribute *ads784x_attributes[] = { 639 &dev_attr_pen_down.attr, 640 &dev_attr_disable.attr, 641 NULL, 642 }; 643 644 static const struct attribute_group ads784x_attr_group = { 645 .attrs = ads784x_attributes, 646 }; 647 648 /*--------------------------------------------------------------------------*/ 649 650 static void null_wait_for_sync(void) 651 { 652 } 653 654 static int ads7846_debounce_filter(void *ads, int data_idx, int *val) 655 { 656 struct ads7846 *ts = ads; 657 658 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 659 /* Start over collecting consistent readings. */ 660 ts->read_rep = 0; 661 /* 662 * Repeat it, if this was the first read or the read 663 * wasn't consistent enough. 664 */ 665 if (ts->read_cnt < ts->debounce_max) { 666 ts->last_read = *val; 667 ts->read_cnt++; 668 return ADS7846_FILTER_REPEAT; 669 } else { 670 /* 671 * Maximum number of debouncing reached and still 672 * not enough number of consistent readings. Abort 673 * the whole sample, repeat it in the next sampling 674 * period. 675 */ 676 ts->read_cnt = 0; 677 return ADS7846_FILTER_IGNORE; 678 } 679 } else { 680 if (++ts->read_rep > ts->debounce_rep) { 681 /* 682 * Got a good reading for this coordinate, 683 * go for the next one. 684 */ 685 ts->read_cnt = 0; 686 ts->read_rep = 0; 687 return ADS7846_FILTER_OK; 688 } else { 689 /* Read more values that are consistent. */ 690 ts->read_cnt++; 691 return ADS7846_FILTER_REPEAT; 692 } 693 } 694 } 695 696 static int ads7846_no_filter(void *ads, int data_idx, int *val) 697 { 698 return ADS7846_FILTER_OK; 699 } 700 701 static int ads7846_get_value(struct ads7846_buf *buf) 702 { 703 int value; 704 705 value = be16_to_cpup(&buf->data); 706 707 /* enforce ADC output is 12 bits width */ 708 return (value >> 3) & 0xfff; 709 } 710 711 static void ads7846_set_cmd_val(struct ads7846 *ts, enum ads7846_cmds cmd_idx, 712 u16 val) 713 { 714 struct ads7846_packet *packet = ts->packet; 715 716 switch (cmd_idx) { 717 case ADS7846_Y: 718 packet->y = val; 719 break; 720 case ADS7846_X: 721 packet->x = val; 722 break; 723 case ADS7846_Z1: 724 packet->z1 = val; 725 break; 726 case ADS7846_Z2: 727 packet->z2 = val; 728 break; 729 default: 730 WARN_ON_ONCE(1); 731 } 732 } 733 734 static u8 ads7846_get_cmd(enum ads7846_cmds cmd_idx, int vref) 735 { 736 switch (cmd_idx) { 737 case ADS7846_Y: 738 return READ_Y(vref); 739 case ADS7846_X: 740 return READ_X(vref); 741 742 /* 7846 specific commands */ 743 case ADS7846_Z1: 744 return READ_Z1(vref); 745 case ADS7846_Z2: 746 return READ_Z2(vref); 747 case ADS7846_PWDOWN: 748 return PWRDOWN; 749 default: 750 WARN_ON_ONCE(1); 751 } 752 753 return 0; 754 } 755 756 static bool ads7846_cmd_need_settle(enum ads7846_cmds cmd_idx) 757 { 758 switch (cmd_idx) { 759 case ADS7846_X: 760 case ADS7846_Y: 761 case ADS7846_Z1: 762 case ADS7846_Z2: 763 return true; 764 case ADS7846_PWDOWN: 765 return false; 766 default: 767 WARN_ON_ONCE(1); 768 } 769 770 return false; 771 } 772 773 static int ads7846_filter(struct ads7846 *ts) 774 { 775 struct ads7846_packet *packet = ts->packet; 776 int action; 777 int val; 778 unsigned int cmd_idx, b; 779 780 packet->ignore = false; 781 for (cmd_idx = packet->last_cmd_idx; cmd_idx < packet->cmds - 1; cmd_idx++) { 782 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 783 784 packet->last_cmd_idx = cmd_idx; 785 786 for (b = l->skip; b < l->count; b++) { 787 val = ads7846_get_value(&packet->rx[l->offset + b]); 788 789 action = ts->filter(ts->filter_data, cmd_idx, &val); 790 if (action == ADS7846_FILTER_REPEAT) { 791 if (b == l->count - 1) 792 return -EAGAIN; 793 } else if (action == ADS7846_FILTER_OK) { 794 ads7846_set_cmd_val(ts, cmd_idx, val); 795 break; 796 } else { 797 packet->ignore = true; 798 return 0; 799 } 800 } 801 } 802 803 return 0; 804 } 805 806 static void ads7846_read_state(struct ads7846 *ts) 807 { 808 struct ads7846_packet *packet = ts->packet; 809 struct spi_message *m; 810 int msg_idx = 0; 811 int error; 812 813 packet->last_cmd_idx = 0; 814 815 while (true) { 816 ts->wait_for_sync(); 817 818 m = &ts->msg[msg_idx]; 819 error = spi_sync(ts->spi, m); 820 if (error) { 821 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 822 packet->ignore = true; 823 return; 824 } 825 826 error = ads7846_filter(ts); 827 if (error) 828 continue; 829 830 return; 831 } 832 } 833 834 static void ads7846_report_state(struct ads7846 *ts) 835 { 836 struct ads7846_packet *packet = ts->packet; 837 unsigned int Rt; 838 u16 x, y, z1, z2; 839 840 x = packet->x; 841 y = packet->y; 842 if (ts->model == 7845) { 843 z1 = 0; 844 z2 = 0; 845 } else { 846 z1 = packet->z1; 847 z2 = packet->z2; 848 } 849 850 /* range filtering */ 851 if (x == MAX_12BIT) 852 x = 0; 853 854 if (ts->model == 7843) { 855 Rt = ts->pressure_max / 2; 856 } else if (ts->model == 7845) { 857 if (get_pendown_state(ts)) 858 Rt = ts->pressure_max / 2; 859 else 860 Rt = 0; 861 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); 862 } else if (likely(x && z1)) { 863 /* compute touch pressure resistance using equation #2 */ 864 Rt = z2; 865 Rt -= z1; 866 Rt *= ts->x_plate_ohms; 867 Rt = DIV_ROUND_CLOSEST(Rt, 16); 868 Rt *= x; 869 Rt /= z1; 870 Rt = DIV_ROUND_CLOSEST(Rt, 256); 871 } else { 872 Rt = 0; 873 } 874 875 /* 876 * Sample found inconsistent by debouncing or pressure is beyond 877 * the maximum. Don't report it to user space, repeat at least 878 * once more the measurement 879 */ 880 if (packet->ignore || Rt > ts->pressure_max) { 881 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", 882 packet->ignore, Rt); 883 return; 884 } 885 886 /* 887 * Maybe check the pendown state before reporting. This discards 888 * false readings when the pen is lifted. 889 */ 890 if (ts->penirq_recheck_delay_usecs) { 891 udelay(ts->penirq_recheck_delay_usecs); 892 if (!get_pendown_state(ts)) 893 Rt = 0; 894 } 895 896 /* 897 * NOTE: We can't rely on the pressure to determine the pen down 898 * state, even this controller has a pressure sensor. The pressure 899 * value can fluctuate for quite a while after lifting the pen and 900 * in some cases may not even settle at the expected value. 901 * 902 * The only safe way to check for the pen up condition is in the 903 * timer by reading the pen signal state (it's a GPIO _and_ IRQ). 904 */ 905 if (Rt) { 906 struct input_dev *input = ts->input; 907 908 if (!ts->pendown) { 909 input_report_key(input, BTN_TOUCH, 1); 910 ts->pendown = true; 911 dev_vdbg(&ts->spi->dev, "DOWN\n"); 912 } 913 914 touchscreen_report_pos(input, &ts->core_prop, x, y, false); 915 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); 916 917 input_sync(input); 918 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); 919 } 920 } 921 922 static irqreturn_t ads7846_hard_irq(int irq, void *handle) 923 { 924 struct ads7846 *ts = handle; 925 926 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; 927 } 928 929 930 static irqreturn_t ads7846_irq(int irq, void *handle) 931 { 932 struct ads7846 *ts = handle; 933 934 /* Start with a small delay before checking pendown state */ 935 msleep(TS_POLL_DELAY); 936 937 while (!ts->stopped && get_pendown_state(ts)) { 938 939 /* pen is down, continue with the measurement */ 940 ads7846_read_state(ts); 941 942 if (!ts->stopped) 943 ads7846_report_state(ts); 944 945 wait_event_timeout(ts->wait, ts->stopped, 946 msecs_to_jiffies(TS_POLL_PERIOD)); 947 } 948 949 if (ts->pendown && !ts->stopped) 950 ads7846_report_pen_up(ts); 951 952 return IRQ_HANDLED; 953 } 954 955 static int __maybe_unused ads7846_suspend(struct device *dev) 956 { 957 struct ads7846 *ts = dev_get_drvdata(dev); 958 959 mutex_lock(&ts->lock); 960 961 if (!ts->suspended) { 962 963 if (!ts->disabled) 964 __ads7846_disable(ts); 965 966 if (device_may_wakeup(&ts->spi->dev)) 967 enable_irq_wake(ts->spi->irq); 968 969 ts->suspended = true; 970 } 971 972 mutex_unlock(&ts->lock); 973 974 return 0; 975 } 976 977 static int __maybe_unused ads7846_resume(struct device *dev) 978 { 979 struct ads7846 *ts = dev_get_drvdata(dev); 980 981 mutex_lock(&ts->lock); 982 983 if (ts->suspended) { 984 985 ts->suspended = false; 986 987 if (device_may_wakeup(&ts->spi->dev)) 988 disable_irq_wake(ts->spi->irq); 989 990 if (!ts->disabled) 991 __ads7846_enable(ts); 992 } 993 994 mutex_unlock(&ts->lock); 995 996 return 0; 997 } 998 999 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); 1000 1001 static int ads7846_setup_pendown(struct spi_device *spi, 1002 struct ads7846 *ts, 1003 const struct ads7846_platform_data *pdata) 1004 { 1005 int err; 1006 1007 /* 1008 * REVISIT when the irq can be triggered active-low, or if for some 1009 * reason the touchscreen isn't hooked up, we don't need to access 1010 * the pendown state. 1011 */ 1012 1013 if (pdata->get_pendown_state) { 1014 ts->get_pendown_state = pdata->get_pendown_state; 1015 } else if (gpio_is_valid(pdata->gpio_pendown)) { 1016 1017 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, 1018 "ads7846_pendown"); 1019 if (err) { 1020 dev_err(&spi->dev, 1021 "failed to request/setup pendown GPIO%d: %d\n", 1022 pdata->gpio_pendown, err); 1023 return err; 1024 } 1025 1026 ts->gpio_pendown = pdata->gpio_pendown; 1027 1028 if (pdata->gpio_pendown_debounce) 1029 gpio_set_debounce(pdata->gpio_pendown, 1030 pdata->gpio_pendown_debounce); 1031 } else { 1032 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); 1033 return -EINVAL; 1034 } 1035 1036 return 0; 1037 } 1038 1039 /* 1040 * Set up the transfers to read touchscreen state; this assumes we 1041 * use formula #2 for pressure, not #3. 1042 */ 1043 static int ads7846_setup_spi_msg(struct ads7846 *ts, 1044 const struct ads7846_platform_data *pdata) 1045 { 1046 struct spi_message *m = &ts->msg[0]; 1047 struct spi_transfer *x = ts->xfer; 1048 struct ads7846_packet *packet = ts->packet; 1049 int vref = pdata->keep_vref_on; 1050 unsigned int count, offset = 0; 1051 unsigned int cmd_idx, b; 1052 unsigned long time; 1053 size_t size = 0; 1054 1055 /* time per bit */ 1056 time = NSEC_PER_SEC / ts->spi->max_speed_hz; 1057 1058 count = pdata->settle_delay_usecs * NSEC_PER_USEC / time; 1059 packet->count_skip = DIV_ROUND_UP(count, 24); 1060 1061 if (ts->debounce_max && ts->debounce_rep) 1062 /* ads7846_debounce_filter() is making ts->debounce_rep + 2 1063 * reads. So we need to get all samples for normal case. */ 1064 packet->count = ts->debounce_rep + 2; 1065 else 1066 packet->count = 1; 1067 1068 if (ts->model == 7846) 1069 packet->cmds = 5; /* x, y, z1, z2, pwdown */ 1070 else 1071 packet->cmds = 3; /* x, y, pwdown */ 1072 1073 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) { 1074 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 1075 unsigned int max_count; 1076 1077 if (ads7846_cmd_need_settle(cmd_idx)) 1078 max_count = packet->count + packet->count_skip; 1079 else 1080 max_count = packet->count; 1081 1082 l->offset = offset; 1083 offset += max_count; 1084 l->count = max_count; 1085 l->skip = packet->count_skip; 1086 size += sizeof(*packet->tx) * max_count; 1087 } 1088 1089 packet->tx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL); 1090 if (!packet->tx) 1091 return -ENOMEM; 1092 1093 packet->rx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL); 1094 if (!packet->rx) 1095 return -ENOMEM; 1096 1097 if (ts->model == 7873) { 1098 /* 1099 * The AD7873 is almost identical to the ADS7846 1100 * keep VREF off during differential/ratiometric 1101 * conversion modes. 1102 */ 1103 ts->model = 7846; 1104 vref = 0; 1105 } 1106 1107 ts->msg_count = 1; 1108 spi_message_init(m); 1109 m->context = ts; 1110 1111 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) { 1112 struct ads7846_buf_layout *l = &packet->l[cmd_idx]; 1113 u8 cmd = ads7846_get_cmd(cmd_idx, vref); 1114 1115 for (b = 0; b < l->count; b++) 1116 packet->tx[l->offset + b].cmd = cmd; 1117 } 1118 1119 x->tx_buf = packet->tx; 1120 x->rx_buf = packet->rx; 1121 x->len = size; 1122 spi_message_add_tail(x, m); 1123 1124 return 0; 1125 } 1126 1127 #ifdef CONFIG_OF 1128 static const struct of_device_id ads7846_dt_ids[] = { 1129 { .compatible = "ti,tsc2046", .data = (void *) 7846 }, 1130 { .compatible = "ti,ads7843", .data = (void *) 7843 }, 1131 { .compatible = "ti,ads7845", .data = (void *) 7845 }, 1132 { .compatible = "ti,ads7846", .data = (void *) 7846 }, 1133 { .compatible = "ti,ads7873", .data = (void *) 7873 }, 1134 { } 1135 }; 1136 MODULE_DEVICE_TABLE(of, ads7846_dt_ids); 1137 1138 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1139 { 1140 struct ads7846_platform_data *pdata; 1141 struct device_node *node = dev->of_node; 1142 const struct of_device_id *match; 1143 u32 value; 1144 1145 if (!node) { 1146 dev_err(dev, "Device does not have associated DT data\n"); 1147 return ERR_PTR(-EINVAL); 1148 } 1149 1150 match = of_match_device(ads7846_dt_ids, dev); 1151 if (!match) { 1152 dev_err(dev, "Unknown device model\n"); 1153 return ERR_PTR(-EINVAL); 1154 } 1155 1156 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 1157 if (!pdata) 1158 return ERR_PTR(-ENOMEM); 1159 1160 pdata->model = (unsigned long)match->data; 1161 1162 of_property_read_u16(node, "ti,vref-delay-usecs", 1163 &pdata->vref_delay_usecs); 1164 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); 1165 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); 1166 1167 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); 1168 1169 of_property_read_u16(node, "ti,settle-delay-usec", 1170 &pdata->settle_delay_usecs); 1171 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", 1172 &pdata->penirq_recheck_delay_usecs); 1173 1174 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); 1175 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); 1176 1177 of_property_read_u16(node, "ti,x-min", &pdata->x_min); 1178 of_property_read_u16(node, "ti,y-min", &pdata->y_min); 1179 of_property_read_u16(node, "ti,x-max", &pdata->x_max); 1180 of_property_read_u16(node, "ti,y-max", &pdata->y_max); 1181 1182 /* 1183 * touchscreen-max-pressure gets parsed during 1184 * touchscreen_parse_properties() 1185 */ 1186 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); 1187 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value)) 1188 pdata->pressure_min = (u16) value; 1189 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); 1190 1191 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); 1192 if (!of_property_read_u32(node, "touchscreen-average-samples", &value)) 1193 pdata->debounce_max = (u16) value; 1194 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); 1195 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); 1196 1197 of_property_read_u32(node, "ti,pendown-gpio-debounce", 1198 &pdata->gpio_pendown_debounce); 1199 1200 pdata->wakeup = of_property_read_bool(node, "wakeup-source") || 1201 of_property_read_bool(node, "linux,wakeup"); 1202 1203 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); 1204 1205 return pdata; 1206 } 1207 #else 1208 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) 1209 { 1210 dev_err(dev, "no platform data defined\n"); 1211 return ERR_PTR(-EINVAL); 1212 } 1213 #endif 1214 1215 static int ads7846_probe(struct spi_device *spi) 1216 { 1217 const struct ads7846_platform_data *pdata; 1218 struct ads7846 *ts; 1219 struct ads7846_packet *packet; 1220 struct input_dev *input_dev; 1221 unsigned long irq_flags; 1222 int err; 1223 1224 if (!spi->irq) { 1225 dev_dbg(&spi->dev, "no IRQ?\n"); 1226 return -EINVAL; 1227 } 1228 1229 /* don't exceed max specified sample rate */ 1230 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 1231 dev_err(&spi->dev, "f(sample) %d KHz?\n", 1232 (spi->max_speed_hz/SAMPLE_BITS)/1000); 1233 return -EINVAL; 1234 } 1235 1236 /* 1237 * We'd set TX word size 8 bits and RX word size to 13 bits ... except 1238 * that even if the hardware can do that, the SPI controller driver 1239 * may not. So we stick to very-portable 8 bit words, both RX and TX. 1240 */ 1241 spi->bits_per_word = 8; 1242 spi->mode &= ~SPI_MODE_X_MASK; 1243 spi->mode |= SPI_MODE_0; 1244 err = spi_setup(spi); 1245 if (err < 0) 1246 return err; 1247 1248 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 1249 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); 1250 input_dev = input_allocate_device(); 1251 if (!ts || !packet || !input_dev) { 1252 err = -ENOMEM; 1253 goto err_free_mem; 1254 } 1255 1256 spi_set_drvdata(spi, ts); 1257 1258 ts->packet = packet; 1259 ts->spi = spi; 1260 ts->input = input_dev; 1261 1262 mutex_init(&ts->lock); 1263 init_waitqueue_head(&ts->wait); 1264 1265 pdata = dev_get_platdata(&spi->dev); 1266 if (!pdata) { 1267 pdata = ads7846_probe_dt(&spi->dev); 1268 if (IS_ERR(pdata)) { 1269 err = PTR_ERR(pdata); 1270 goto err_free_mem; 1271 } 1272 } 1273 1274 ts->model = pdata->model ? : 7846; 1275 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 1276 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 1277 ts->vref_mv = pdata->vref_mv; 1278 1279 if (pdata->filter != NULL) { 1280 if (pdata->filter_init != NULL) { 1281 err = pdata->filter_init(pdata, &ts->filter_data); 1282 if (err < 0) 1283 goto err_free_mem; 1284 } 1285 ts->filter = pdata->filter; 1286 ts->filter_cleanup = pdata->filter_cleanup; 1287 } else if (pdata->debounce_max) { 1288 ts->debounce_max = pdata->debounce_max; 1289 if (ts->debounce_max < 2) 1290 ts->debounce_max = 2; 1291 ts->debounce_tol = pdata->debounce_tol; 1292 ts->debounce_rep = pdata->debounce_rep; 1293 ts->filter = ads7846_debounce_filter; 1294 ts->filter_data = ts; 1295 } else { 1296 ts->filter = ads7846_no_filter; 1297 } 1298 1299 err = ads7846_setup_pendown(spi, ts, pdata); 1300 if (err) 1301 goto err_cleanup_filter; 1302 1303 if (pdata->penirq_recheck_delay_usecs) 1304 ts->penirq_recheck_delay_usecs = 1305 pdata->penirq_recheck_delay_usecs; 1306 1307 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; 1308 1309 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 1310 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); 1311 1312 input_dev->name = ts->name; 1313 input_dev->phys = ts->phys; 1314 input_dev->dev.parent = &spi->dev; 1315 1316 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 1317 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 1318 input_set_abs_params(input_dev, ABS_X, 1319 pdata->x_min ? : 0, 1320 pdata->x_max ? : MAX_12BIT, 1321 0, 0); 1322 input_set_abs_params(input_dev, ABS_Y, 1323 pdata->y_min ? : 0, 1324 pdata->y_max ? : MAX_12BIT, 1325 0, 0); 1326 input_set_abs_params(input_dev, ABS_PRESSURE, 1327 pdata->pressure_min, pdata->pressure_max, 0, 0); 1328 1329 /* 1330 * Parse common framework properties. Must be done here to ensure the 1331 * correct behaviour in case of using the legacy vendor bindings. The 1332 * general binding value overrides the vendor specific one. 1333 */ 1334 touchscreen_parse_properties(ts->input, false, &ts->core_prop); 1335 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0; 1336 1337 /* 1338 * Check if legacy ti,swap-xy binding is used instead of 1339 * touchscreen-swapped-x-y 1340 */ 1341 if (!ts->core_prop.swap_x_y && pdata->swap_xy) { 1342 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]); 1343 ts->core_prop.swap_x_y = true; 1344 } 1345 1346 ads7846_setup_spi_msg(ts, pdata); 1347 1348 ts->reg = regulator_get(&spi->dev, "vcc"); 1349 if (IS_ERR(ts->reg)) { 1350 err = PTR_ERR(ts->reg); 1351 dev_err(&spi->dev, "unable to get regulator: %d\n", err); 1352 goto err_free_gpio; 1353 } 1354 1355 err = regulator_enable(ts->reg); 1356 if (err) { 1357 dev_err(&spi->dev, "unable to enable regulator: %d\n", err); 1358 goto err_put_regulator; 1359 } 1360 1361 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; 1362 irq_flags |= IRQF_ONESHOT; 1363 1364 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, 1365 irq_flags, spi->dev.driver->name, ts); 1366 if (err && !pdata->irq_flags) { 1367 dev_info(&spi->dev, 1368 "trying pin change workaround on irq %d\n", spi->irq); 1369 irq_flags |= IRQF_TRIGGER_RISING; 1370 err = request_threaded_irq(spi->irq, 1371 ads7846_hard_irq, ads7846_irq, 1372 irq_flags, spi->dev.driver->name, ts); 1373 } 1374 1375 if (err) { 1376 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 1377 goto err_disable_regulator; 1378 } 1379 1380 err = ads784x_hwmon_register(spi, ts); 1381 if (err) 1382 goto err_free_irq; 1383 1384 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 1385 1386 /* 1387 * Take a first sample, leaving nPENIRQ active and vREF off; avoid 1388 * the touchscreen, in case it's not connected. 1389 */ 1390 if (ts->model == 7845) 1391 ads7845_read12_ser(&spi->dev, PWRDOWN); 1392 else 1393 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); 1394 1395 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); 1396 if (err) 1397 goto err_remove_hwmon; 1398 1399 err = input_register_device(input_dev); 1400 if (err) 1401 goto err_remove_attr_group; 1402 1403 device_init_wakeup(&spi->dev, pdata->wakeup); 1404 1405 /* 1406 * If device does not carry platform data we must have allocated it 1407 * when parsing DT data. 1408 */ 1409 if (!dev_get_platdata(&spi->dev)) 1410 devm_kfree(&spi->dev, (void *)pdata); 1411 1412 return 0; 1413 1414 err_remove_attr_group: 1415 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1416 err_remove_hwmon: 1417 ads784x_hwmon_unregister(spi, ts); 1418 err_free_irq: 1419 free_irq(spi->irq, ts); 1420 err_disable_regulator: 1421 regulator_disable(ts->reg); 1422 err_put_regulator: 1423 regulator_put(ts->reg); 1424 err_free_gpio: 1425 if (!ts->get_pendown_state) 1426 gpio_free(ts->gpio_pendown); 1427 err_cleanup_filter: 1428 if (ts->filter_cleanup) 1429 ts->filter_cleanup(ts->filter_data); 1430 err_free_mem: 1431 input_free_device(input_dev); 1432 kfree(packet); 1433 kfree(ts); 1434 return err; 1435 } 1436 1437 static int ads7846_remove(struct spi_device *spi) 1438 { 1439 struct ads7846 *ts = spi_get_drvdata(spi); 1440 1441 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); 1442 1443 ads7846_disable(ts); 1444 free_irq(ts->spi->irq, ts); 1445 1446 input_unregister_device(ts->input); 1447 1448 ads784x_hwmon_unregister(spi, ts); 1449 1450 regulator_put(ts->reg); 1451 1452 if (!ts->get_pendown_state) { 1453 /* 1454 * If we are not using specialized pendown method we must 1455 * have been relying on gpio we set up ourselves. 1456 */ 1457 gpio_free(ts->gpio_pendown); 1458 } 1459 1460 if (ts->filter_cleanup) 1461 ts->filter_cleanup(ts->filter_data); 1462 1463 kfree(ts->packet); 1464 kfree(ts); 1465 1466 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 1467 1468 return 0; 1469 } 1470 1471 static struct spi_driver ads7846_driver = { 1472 .driver = { 1473 .name = "ads7846", 1474 .pm = &ads7846_pm, 1475 .of_match_table = of_match_ptr(ads7846_dt_ids), 1476 }, 1477 .probe = ads7846_probe, 1478 .remove = ads7846_remove, 1479 }; 1480 1481 module_spi_driver(ads7846_driver); 1482 1483 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 1484 MODULE_LICENSE("GPL"); 1485 MODULE_ALIAS("spi:ads7846"); 1486