1 /* 2 * TSC2004/TSC2005 touchscreen driver core 3 * 4 * Copyright (C) 2006-2010 Nokia Corporation 5 * Copyright (C) 2015 QWERTY Embedded Design 6 * Copyright (C) 2015 EMAC Inc. 7 * 8 * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com> 9 * based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 */ 21 22 #include <linux/kernel.h> 23 #include <linux/module.h> 24 #include <linux/input.h> 25 #include <linux/input/touchscreen.h> 26 #include <linux/interrupt.h> 27 #include <linux/delay.h> 28 #include <linux/pm.h> 29 #include <linux/of.h> 30 #include <linux/spi/tsc2005.h> 31 #include <linux/regulator/consumer.h> 32 #include <linux/regmap.h> 33 #include <linux/gpio/consumer.h> 34 #include "tsc200x-core.h" 35 36 /* 37 * The touchscreen interface operates as follows: 38 * 39 * 1) Pen is pressed against the touchscreen. 40 * 2) TSC200X performs AD conversion. 41 * 3) After the conversion is done TSC200X drives DAV line down. 42 * 4) GPIO IRQ is received and tsc200x_irq_thread() is scheduled. 43 * 5) tsc200x_irq_thread() queues up a transfer to fetch the x, y, z1, z2 44 * values. 45 * 6) tsc200x_irq_thread() reports coordinates to input layer and sets up 46 * tsc200x_penup_timer() to be called after TSC200X_PENUP_TIME_MS (40ms). 47 * 7) When the penup timer expires, there have not been touch or DAV interrupts 48 * during the last 40ms which means the pen has been lifted. 49 * 50 * ESD recovery via a hardware reset is done if the TSC200X doesn't respond 51 * after a configurable period (in ms) of activity. If esd_timeout is 0, the 52 * watchdog is disabled. 53 */ 54 55 static const struct regmap_range tsc200x_writable_ranges[] = { 56 regmap_reg_range(TSC200X_REG_AUX_HIGH, TSC200X_REG_CFR2), 57 }; 58 59 static const struct regmap_access_table tsc200x_writable_table = { 60 .yes_ranges = tsc200x_writable_ranges, 61 .n_yes_ranges = ARRAY_SIZE(tsc200x_writable_ranges), 62 }; 63 64 const struct regmap_config tsc200x_regmap_config = { 65 .reg_bits = 8, 66 .val_bits = 16, 67 .reg_stride = 0x08, 68 .max_register = 0x78, 69 .read_flag_mask = TSC200X_REG_READ, 70 .write_flag_mask = TSC200X_REG_PND0, 71 .wr_table = &tsc200x_writable_table, 72 .use_single_rw = true, 73 }; 74 EXPORT_SYMBOL_GPL(tsc200x_regmap_config); 75 76 struct tsc200x_data { 77 u16 x; 78 u16 y; 79 u16 z1; 80 u16 z2; 81 } __packed; 82 #define TSC200X_DATA_REGS 4 83 84 struct tsc200x { 85 struct device *dev; 86 struct regmap *regmap; 87 __u16 bustype; 88 89 struct input_dev *idev; 90 char phys[32]; 91 92 struct mutex mutex; 93 94 /* raw copy of previous x,y,z */ 95 int in_x; 96 int in_y; 97 int in_z1; 98 int in_z2; 99 100 spinlock_t lock; 101 struct timer_list penup_timer; 102 103 unsigned int esd_timeout; 104 struct delayed_work esd_work; 105 unsigned long last_valid_interrupt; 106 107 unsigned int x_plate_ohm; 108 109 bool opened; 110 bool suspended; 111 112 bool pen_down; 113 114 struct regulator *vio; 115 116 struct gpio_desc *reset_gpio; 117 void (*set_reset)(bool enable); 118 int (*tsc200x_cmd)(struct device *dev, u8 cmd); 119 int irq; 120 }; 121 122 static void tsc200x_update_pen_state(struct tsc200x *ts, 123 int x, int y, int pressure) 124 { 125 if (pressure) { 126 input_report_abs(ts->idev, ABS_X, x); 127 input_report_abs(ts->idev, ABS_Y, y); 128 input_report_abs(ts->idev, ABS_PRESSURE, pressure); 129 if (!ts->pen_down) { 130 input_report_key(ts->idev, BTN_TOUCH, !!pressure); 131 ts->pen_down = true; 132 } 133 } else { 134 input_report_abs(ts->idev, ABS_PRESSURE, 0); 135 if (ts->pen_down) { 136 input_report_key(ts->idev, BTN_TOUCH, 0); 137 ts->pen_down = false; 138 } 139 } 140 input_sync(ts->idev); 141 dev_dbg(ts->dev, "point(%4d,%4d), pressure (%4d)\n", x, y, 142 pressure); 143 } 144 145 static irqreturn_t tsc200x_irq_thread(int irq, void *_ts) 146 { 147 struct tsc200x *ts = _ts; 148 unsigned long flags; 149 unsigned int pressure; 150 struct tsc200x_data tsdata; 151 int error; 152 153 /* read the coordinates */ 154 error = regmap_bulk_read(ts->regmap, TSC200X_REG_X, &tsdata, 155 TSC200X_DATA_REGS); 156 if (unlikely(error)) 157 goto out; 158 159 /* validate position */ 160 if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT)) 161 goto out; 162 163 /* Skip reading if the pressure components are out of range */ 164 if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT)) 165 goto out; 166 if (unlikely(tsdata.z1 >= tsdata.z2)) 167 goto out; 168 169 /* 170 * Skip point if this is a pen down with the exact same values as 171 * the value before pen-up - that implies SPI fed us stale data 172 */ 173 if (!ts->pen_down && 174 ts->in_x == tsdata.x && ts->in_y == tsdata.y && 175 ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) { 176 goto out; 177 } 178 179 /* 180 * At this point we are happy we have a valid and useful reading. 181 * Remember it for later comparisons. We may now begin downsampling. 182 */ 183 ts->in_x = tsdata.x; 184 ts->in_y = tsdata.y; 185 ts->in_z1 = tsdata.z1; 186 ts->in_z2 = tsdata.z2; 187 188 /* Compute touch pressure resistance using equation #1 */ 189 pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1; 190 pressure = pressure * ts->x_plate_ohm / 4096; 191 if (unlikely(pressure > MAX_12BIT)) 192 goto out; 193 194 spin_lock_irqsave(&ts->lock, flags); 195 196 tsc200x_update_pen_state(ts, tsdata.x, tsdata.y, pressure); 197 mod_timer(&ts->penup_timer, 198 jiffies + msecs_to_jiffies(TSC200X_PENUP_TIME_MS)); 199 200 spin_unlock_irqrestore(&ts->lock, flags); 201 202 ts->last_valid_interrupt = jiffies; 203 out: 204 return IRQ_HANDLED; 205 } 206 207 static void tsc200x_penup_timer(unsigned long data) 208 { 209 struct tsc200x *ts = (struct tsc200x *)data; 210 unsigned long flags; 211 212 spin_lock_irqsave(&ts->lock, flags); 213 tsc200x_update_pen_state(ts, 0, 0, 0); 214 spin_unlock_irqrestore(&ts->lock, flags); 215 } 216 217 static void tsc200x_start_scan(struct tsc200x *ts) 218 { 219 regmap_write(ts->regmap, TSC200X_REG_CFR0, TSC200X_CFR0_INITVALUE); 220 regmap_write(ts->regmap, TSC200X_REG_CFR1, TSC200X_CFR1_INITVALUE); 221 regmap_write(ts->regmap, TSC200X_REG_CFR2, TSC200X_CFR2_INITVALUE); 222 ts->tsc200x_cmd(ts->dev, TSC200X_CMD_NORMAL); 223 } 224 225 static void tsc200x_stop_scan(struct tsc200x *ts) 226 { 227 ts->tsc200x_cmd(ts->dev, TSC200X_CMD_STOP); 228 } 229 230 static void tsc200x_set_reset(struct tsc200x *ts, bool enable) 231 { 232 if (ts->reset_gpio) 233 gpiod_set_value_cansleep(ts->reset_gpio, enable); 234 else if (ts->set_reset) 235 ts->set_reset(enable); 236 } 237 238 /* must be called with ts->mutex held */ 239 static void __tsc200x_disable(struct tsc200x *ts) 240 { 241 tsc200x_stop_scan(ts); 242 243 disable_irq(ts->irq); 244 del_timer_sync(&ts->penup_timer); 245 246 cancel_delayed_work_sync(&ts->esd_work); 247 248 enable_irq(ts->irq); 249 } 250 251 /* must be called with ts->mutex held */ 252 static void __tsc200x_enable(struct tsc200x *ts) 253 { 254 tsc200x_start_scan(ts); 255 256 if (ts->esd_timeout && (ts->set_reset || ts->reset_gpio)) { 257 ts->last_valid_interrupt = jiffies; 258 schedule_delayed_work(&ts->esd_work, 259 round_jiffies_relative( 260 msecs_to_jiffies(ts->esd_timeout))); 261 } 262 } 263 264 static ssize_t tsc200x_selftest_show(struct device *dev, 265 struct device_attribute *attr, 266 char *buf) 267 { 268 struct tsc200x *ts = dev_get_drvdata(dev); 269 unsigned int temp_high; 270 unsigned int temp_high_orig; 271 unsigned int temp_high_test; 272 bool success = true; 273 int error; 274 275 mutex_lock(&ts->mutex); 276 277 /* 278 * Test TSC200X communications via temp high register. 279 */ 280 __tsc200x_disable(ts); 281 282 error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high_orig); 283 if (error) { 284 dev_warn(dev, "selftest failed: read error %d\n", error); 285 success = false; 286 goto out; 287 } 288 289 temp_high_test = (temp_high_orig - 1) & MAX_12BIT; 290 291 error = regmap_write(ts->regmap, TSC200X_REG_TEMP_HIGH, temp_high_test); 292 if (error) { 293 dev_warn(dev, "selftest failed: write error %d\n", error); 294 success = false; 295 goto out; 296 } 297 298 error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high); 299 if (error) { 300 dev_warn(dev, "selftest failed: read error %d after write\n", 301 error); 302 success = false; 303 goto out; 304 } 305 306 if (temp_high != temp_high_test) { 307 dev_warn(dev, "selftest failed: %d != %d\n", 308 temp_high, temp_high_test); 309 success = false; 310 } 311 312 /* hardware reset */ 313 tsc200x_set_reset(ts, false); 314 usleep_range(100, 500); /* only 10us required */ 315 tsc200x_set_reset(ts, true); 316 317 if (!success) 318 goto out; 319 320 /* test that the reset really happened */ 321 error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high); 322 if (error) { 323 dev_warn(dev, "selftest failed: read error %d after reset\n", 324 error); 325 success = false; 326 goto out; 327 } 328 329 if (temp_high != temp_high_orig) { 330 dev_warn(dev, "selftest failed after reset: %d != %d\n", 331 temp_high, temp_high_orig); 332 success = false; 333 } 334 335 out: 336 __tsc200x_enable(ts); 337 mutex_unlock(&ts->mutex); 338 339 return sprintf(buf, "%d\n", success); 340 } 341 342 static DEVICE_ATTR(selftest, S_IRUGO, tsc200x_selftest_show, NULL); 343 344 static struct attribute *tsc200x_attrs[] = { 345 &dev_attr_selftest.attr, 346 NULL 347 }; 348 349 static umode_t tsc200x_attr_is_visible(struct kobject *kobj, 350 struct attribute *attr, int n) 351 { 352 struct device *dev = container_of(kobj, struct device, kobj); 353 struct tsc200x *ts = dev_get_drvdata(dev); 354 umode_t mode = attr->mode; 355 356 if (attr == &dev_attr_selftest.attr) { 357 if (!ts->set_reset && !ts->reset_gpio) 358 mode = 0; 359 } 360 361 return mode; 362 } 363 364 static const struct attribute_group tsc200x_attr_group = { 365 .is_visible = tsc200x_attr_is_visible, 366 .attrs = tsc200x_attrs, 367 }; 368 369 static void tsc200x_esd_work(struct work_struct *work) 370 { 371 struct tsc200x *ts = container_of(work, struct tsc200x, esd_work.work); 372 int error; 373 unsigned int r; 374 375 if (!mutex_trylock(&ts->mutex)) { 376 /* 377 * If the mutex is taken, it means that disable or enable is in 378 * progress. In that case just reschedule the work. If the work 379 * is not needed, it will be canceled by disable. 380 */ 381 goto reschedule; 382 } 383 384 if (time_is_after_jiffies(ts->last_valid_interrupt + 385 msecs_to_jiffies(ts->esd_timeout))) 386 goto out; 387 388 /* We should be able to read register without disabling interrupts. */ 389 error = regmap_read(ts->regmap, TSC200X_REG_CFR0, &r); 390 if (!error && 391 !((r ^ TSC200X_CFR0_INITVALUE) & TSC200X_CFR0_RW_MASK)) { 392 goto out; 393 } 394 395 /* 396 * If we could not read our known value from configuration register 0 397 * then we should reset the controller as if from power-up and start 398 * scanning again. 399 */ 400 dev_info(ts->dev, "TSC200X not responding - resetting\n"); 401 402 disable_irq(ts->irq); 403 del_timer_sync(&ts->penup_timer); 404 405 tsc200x_update_pen_state(ts, 0, 0, 0); 406 407 tsc200x_set_reset(ts, false); 408 usleep_range(100, 500); /* only 10us required */ 409 tsc200x_set_reset(ts, true); 410 411 enable_irq(ts->irq); 412 tsc200x_start_scan(ts); 413 414 out: 415 mutex_unlock(&ts->mutex); 416 reschedule: 417 /* re-arm the watchdog */ 418 schedule_delayed_work(&ts->esd_work, 419 round_jiffies_relative( 420 msecs_to_jiffies(ts->esd_timeout))); 421 } 422 423 static int tsc200x_open(struct input_dev *input) 424 { 425 struct tsc200x *ts = input_get_drvdata(input); 426 427 mutex_lock(&ts->mutex); 428 429 if (!ts->suspended) 430 __tsc200x_enable(ts); 431 432 ts->opened = true; 433 434 mutex_unlock(&ts->mutex); 435 436 return 0; 437 } 438 439 static void tsc200x_close(struct input_dev *input) 440 { 441 struct tsc200x *ts = input_get_drvdata(input); 442 443 mutex_lock(&ts->mutex); 444 445 if (!ts->suspended) 446 __tsc200x_disable(ts); 447 448 ts->opened = false; 449 450 mutex_unlock(&ts->mutex); 451 } 452 453 int tsc200x_probe(struct device *dev, int irq, const struct input_id *tsc_id, 454 struct regmap *regmap, 455 int (*tsc200x_cmd)(struct device *dev, u8 cmd)) 456 { 457 const struct tsc2005_platform_data *pdata = dev_get_platdata(dev); 458 struct device_node *np = dev->of_node; 459 460 struct tsc200x *ts; 461 struct input_dev *input_dev; 462 unsigned int max_x = MAX_12BIT; 463 unsigned int max_y = MAX_12BIT; 464 unsigned int max_p = MAX_12BIT; 465 unsigned int fudge_x = TSC200X_DEF_X_FUZZ; 466 unsigned int fudge_y = TSC200X_DEF_Y_FUZZ; 467 unsigned int fudge_p = TSC200X_DEF_P_FUZZ; 468 unsigned int x_plate_ohm = TSC200X_DEF_RESISTOR; 469 unsigned int esd_timeout; 470 int error; 471 472 if (!np && !pdata) { 473 dev_err(dev, "no platform data\n"); 474 return -ENODEV; 475 } 476 477 if (irq <= 0) { 478 dev_err(dev, "no irq\n"); 479 return -ENODEV; 480 } 481 482 if (IS_ERR(regmap)) 483 return PTR_ERR(regmap); 484 485 if (!tsc200x_cmd) { 486 dev_err(dev, "no cmd function\n"); 487 return -ENODEV; 488 } 489 490 if (pdata) { 491 fudge_x = pdata->ts_x_fudge; 492 fudge_y = pdata->ts_y_fudge; 493 fudge_p = pdata->ts_pressure_fudge; 494 max_x = pdata->ts_x_max; 495 max_y = pdata->ts_y_max; 496 max_p = pdata->ts_pressure_max; 497 x_plate_ohm = pdata->ts_x_plate_ohm; 498 esd_timeout = pdata->esd_timeout_ms; 499 } else { 500 x_plate_ohm = TSC200X_DEF_RESISTOR; 501 of_property_read_u32(np, "ti,x-plate-ohms", &x_plate_ohm); 502 esd_timeout = 0; 503 of_property_read_u32(np, "ti,esd-recovery-timeout-ms", 504 &esd_timeout); 505 } 506 507 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); 508 if (!ts) 509 return -ENOMEM; 510 511 input_dev = devm_input_allocate_device(dev); 512 if (!input_dev) 513 return -ENOMEM; 514 515 ts->irq = irq; 516 ts->dev = dev; 517 ts->idev = input_dev; 518 ts->regmap = regmap; 519 ts->tsc200x_cmd = tsc200x_cmd; 520 ts->x_plate_ohm = x_plate_ohm; 521 ts->esd_timeout = esd_timeout; 522 523 ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); 524 if (IS_ERR(ts->reset_gpio)) { 525 error = PTR_ERR(ts->reset_gpio); 526 dev_err(dev, "error acquiring reset gpio: %d\n", error); 527 return error; 528 } 529 530 ts->vio = devm_regulator_get(dev, "vio"); 531 if (IS_ERR(ts->vio)) { 532 error = PTR_ERR(ts->vio); 533 dev_err(dev, "error acquiring vio regulator: %d", error); 534 return error; 535 } 536 537 if (!ts->reset_gpio && pdata) 538 ts->set_reset = pdata->set_reset; 539 540 mutex_init(&ts->mutex); 541 542 spin_lock_init(&ts->lock); 543 setup_timer(&ts->penup_timer, tsc200x_penup_timer, (unsigned long)ts); 544 545 INIT_DELAYED_WORK(&ts->esd_work, tsc200x_esd_work); 546 547 snprintf(ts->phys, sizeof(ts->phys), 548 "%s/input-ts", dev_name(dev)); 549 550 if (tsc_id->product == 2004) { 551 input_dev->name = "TSC200X touchscreen"; 552 } else { 553 input_dev->name = devm_kasprintf(dev, GFP_KERNEL, 554 "TSC%04d touchscreen", 555 tsc_id->product); 556 if (!input_dev->name) 557 return -ENOMEM; 558 } 559 560 input_dev->phys = ts->phys; 561 input_dev->id = *tsc_id; 562 input_dev->dev.parent = dev; 563 input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY); 564 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 565 566 input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0); 567 input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0); 568 input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0); 569 570 if (np) 571 touchscreen_parse_properties(input_dev, false, NULL); 572 573 input_dev->open = tsc200x_open; 574 input_dev->close = tsc200x_close; 575 576 input_set_drvdata(input_dev, ts); 577 578 /* Ensure the touchscreen is off */ 579 tsc200x_stop_scan(ts); 580 581 error = devm_request_threaded_irq(dev, irq, NULL, 582 tsc200x_irq_thread, 583 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 584 "tsc200x", ts); 585 if (error) { 586 dev_err(dev, "Failed to request irq, err: %d\n", error); 587 return error; 588 } 589 590 error = regulator_enable(ts->vio); 591 if (error) 592 return error; 593 594 dev_set_drvdata(dev, ts); 595 error = sysfs_create_group(&dev->kobj, &tsc200x_attr_group); 596 if (error) { 597 dev_err(dev, 598 "Failed to create sysfs attributes, err: %d\n", error); 599 goto disable_regulator; 600 } 601 602 error = input_register_device(ts->idev); 603 if (error) { 604 dev_err(dev, 605 "Failed to register input device, err: %d\n", error); 606 goto err_remove_sysfs; 607 } 608 609 irq_set_irq_wake(irq, 1); 610 return 0; 611 612 err_remove_sysfs: 613 sysfs_remove_group(&dev->kobj, &tsc200x_attr_group); 614 disable_regulator: 615 regulator_disable(ts->vio); 616 return error; 617 } 618 EXPORT_SYMBOL_GPL(tsc200x_probe); 619 620 int tsc200x_remove(struct device *dev) 621 { 622 struct tsc200x *ts = dev_get_drvdata(dev); 623 624 sysfs_remove_group(&dev->kobj, &tsc200x_attr_group); 625 626 regulator_disable(ts->vio); 627 628 return 0; 629 } 630 EXPORT_SYMBOL_GPL(tsc200x_remove); 631 632 static int __maybe_unused tsc200x_suspend(struct device *dev) 633 { 634 struct tsc200x *ts = dev_get_drvdata(dev); 635 636 mutex_lock(&ts->mutex); 637 638 if (!ts->suspended && ts->opened) 639 __tsc200x_disable(ts); 640 641 ts->suspended = true; 642 643 mutex_unlock(&ts->mutex); 644 645 return 0; 646 } 647 648 static int __maybe_unused tsc200x_resume(struct device *dev) 649 { 650 struct tsc200x *ts = dev_get_drvdata(dev); 651 652 mutex_lock(&ts->mutex); 653 654 if (ts->suspended && ts->opened) 655 __tsc200x_enable(ts); 656 657 ts->suspended = false; 658 659 mutex_unlock(&ts->mutex); 660 661 return 0; 662 } 663 664 SIMPLE_DEV_PM_OPS(tsc200x_pm_ops, tsc200x_suspend, tsc200x_resume); 665 EXPORT_SYMBOL_GPL(tsc200x_pm_ops); 666 667 MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>"); 668 MODULE_DESCRIPTION("TSC200x Touchscreen Driver Core"); 669 MODULE_LICENSE("GPL"); 670