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