1 /* 2 * AD7879/AD7889 based touchscreen and GPIO driver 3 * 4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 * 8 * History: 9 * Copyright (c) 2005 David Brownell 10 * Copyright (c) 2006 Nokia Corporation 11 * Various changes: Imre Deak <imre.deak@nokia.com> 12 * 13 * Using code from: 14 * - corgi_ts.c 15 * Copyright (C) 2004-2005 Richard Purdie 16 * - omap_ts.[hc], ads7846.h, ts_osk.c 17 * Copyright (C) 2002 MontaVista Software 18 * Copyright (C) 2004 Texas Instruments 19 * Copyright (C) 2005 Dirk Behme 20 * - ad7877.c 21 * Copyright (C) 2006-2008 Analog Devices Inc. 22 */ 23 24 #include <linux/device.h> 25 #include <linux/delay.h> 26 #include <linux/input.h> 27 #include <linux/interrupt.h> 28 #include <linux/irq.h> 29 #include <linux/slab.h> 30 #include <linux/spi/spi.h> 31 #include <linux/i2c.h> 32 #include <linux/gpio.h> 33 34 #include <linux/spi/ad7879.h> 35 #include <linux/module.h> 36 #include "ad7879.h" 37 38 #define AD7879_REG_ZEROS 0 39 #define AD7879_REG_CTRL1 1 40 #define AD7879_REG_CTRL2 2 41 #define AD7879_REG_CTRL3 3 42 #define AD7879_REG_AUX1HIGH 4 43 #define AD7879_REG_AUX1LOW 5 44 #define AD7879_REG_TEMP1HIGH 6 45 #define AD7879_REG_TEMP1LOW 7 46 #define AD7879_REG_XPLUS 8 47 #define AD7879_REG_YPLUS 9 48 #define AD7879_REG_Z1 10 49 #define AD7879_REG_Z2 11 50 #define AD7879_REG_AUXVBAT 12 51 #define AD7879_REG_TEMP 13 52 #define AD7879_REG_REVID 14 53 54 /* Control REG 1 */ 55 #define AD7879_TMR(x) ((x & 0xFF) << 0) 56 #define AD7879_ACQ(x) ((x & 0x3) << 8) 57 #define AD7879_MODE_NOC (0 << 10) /* Do not convert */ 58 #define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */ 59 #define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */ 60 #define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */ 61 #define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */ 62 63 /* Control REG 2 */ 64 #define AD7879_FCD(x) ((x & 0x3) << 0) 65 #define AD7879_RESET (1 << 4) 66 #define AD7879_MFS(x) ((x & 0x3) << 5) 67 #define AD7879_AVG(x) ((x & 0x3) << 7) 68 #define AD7879_SER (1 << 9) /* non-differential */ 69 #define AD7879_DFR (0 << 9) /* differential */ 70 #define AD7879_GPIOPOL (1 << 10) 71 #define AD7879_GPIODIR (1 << 11) 72 #define AD7879_GPIO_DATA (1 << 12) 73 #define AD7879_GPIO_EN (1 << 13) 74 #define AD7879_PM(x) ((x & 0x3) << 14) 75 #define AD7879_PM_SHUTDOWN (0) 76 #define AD7879_PM_DYN (1) 77 #define AD7879_PM_FULLON (2) 78 79 /* Control REG 3 */ 80 #define AD7879_TEMPMASK_BIT (1<<15) 81 #define AD7879_AUXVBATMASK_BIT (1<<14) 82 #define AD7879_INTMODE_BIT (1<<13) 83 #define AD7879_GPIOALERTMASK_BIT (1<<12) 84 #define AD7879_AUXLOW_BIT (1<<11) 85 #define AD7879_AUXHIGH_BIT (1<<10) 86 #define AD7879_TEMPLOW_BIT (1<<9) 87 #define AD7879_TEMPHIGH_BIT (1<<8) 88 #define AD7879_YPLUS_BIT (1<<7) 89 #define AD7879_XPLUS_BIT (1<<6) 90 #define AD7879_Z1_BIT (1<<5) 91 #define AD7879_Z2_BIT (1<<4) 92 #define AD7879_AUX_BIT (1<<3) 93 #define AD7879_VBAT_BIT (1<<2) 94 #define AD7879_TEMP_BIT (1<<1) 95 96 enum { 97 AD7879_SEQ_XPOS = 0, 98 AD7879_SEQ_YPOS = 1, 99 AD7879_SEQ_Z1 = 2, 100 AD7879_SEQ_Z2 = 3, 101 AD7879_NR_SENSE = 4, 102 }; 103 104 #define MAX_12BIT ((1<<12)-1) 105 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50) 106 107 struct ad7879 { 108 const struct ad7879_bus_ops *bops; 109 110 struct device *dev; 111 struct input_dev *input; 112 struct timer_list timer; 113 #ifdef CONFIG_GPIOLIB 114 struct gpio_chip gc; 115 struct mutex mutex; 116 #endif 117 unsigned int irq; 118 bool disabled; /* P: input->mutex */ 119 bool suspended; /* P: input->mutex */ 120 bool swap_xy; 121 u16 conversion_data[AD7879_NR_SENSE]; 122 char phys[32]; 123 u8 first_conversion_delay; 124 u8 acquisition_time; 125 u8 averaging; 126 u8 pen_down_acc_interval; 127 u8 median; 128 u16 x_plate_ohms; 129 u16 pressure_max; 130 u16 cmd_crtl1; 131 u16 cmd_crtl2; 132 u16 cmd_crtl3; 133 int x; 134 int y; 135 int Rt; 136 }; 137 138 static int ad7879_read(struct ad7879 *ts, u8 reg) 139 { 140 return ts->bops->read(ts->dev, reg); 141 } 142 143 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf) 144 { 145 return ts->bops->multi_read(ts->dev, first_reg, count, buf); 146 } 147 148 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val) 149 { 150 return ts->bops->write(ts->dev, reg, val); 151 } 152 153 static int ad7879_report(struct ad7879 *ts) 154 { 155 struct input_dev *input_dev = ts->input; 156 unsigned Rt; 157 u16 x, y, z1, z2; 158 159 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT; 160 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT; 161 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT; 162 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT; 163 164 if (ts->swap_xy) 165 swap(x, y); 166 167 /* 168 * The samples processed here are already preprocessed by the AD7879. 169 * The preprocessing function consists of a median and an averaging 170 * filter. The combination of these two techniques provides a robust 171 * solution, discarding the spurious noise in the signal and keeping 172 * only the data of interest. The size of both filters is 173 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other 174 * user-programmable conversion controls include variable acquisition 175 * time, and first conversion delay. Up to 16 averages can be taken 176 * per conversion. 177 */ 178 179 if (likely(x && z1)) { 180 /* compute touch pressure resistance using equation #1 */ 181 Rt = (z2 - z1) * x * ts->x_plate_ohms; 182 Rt /= z1; 183 Rt = (Rt + 2047) >> 12; 184 185 /* 186 * Sample found inconsistent, pressure is beyond 187 * the maximum. Don't report it to user space. 188 */ 189 if (Rt > ts->pressure_max) 190 return -EINVAL; 191 192 /* 193 * Note that we delay reporting events by one sample. 194 * This is done to avoid reporting last sample of the 195 * touch sequence, which may be incomplete if finger 196 * leaves the surface before last reading is taken. 197 */ 198 if (timer_pending(&ts->timer)) { 199 /* Touch continues */ 200 input_report_key(input_dev, BTN_TOUCH, 1); 201 input_report_abs(input_dev, ABS_X, ts->x); 202 input_report_abs(input_dev, ABS_Y, ts->y); 203 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt); 204 input_sync(input_dev); 205 } 206 207 ts->x = x; 208 ts->y = y; 209 ts->Rt = Rt; 210 211 return 0; 212 } 213 214 return -EINVAL; 215 } 216 217 static void ad7879_ts_event_release(struct ad7879 *ts) 218 { 219 struct input_dev *input_dev = ts->input; 220 221 input_report_abs(input_dev, ABS_PRESSURE, 0); 222 input_report_key(input_dev, BTN_TOUCH, 0); 223 input_sync(input_dev); 224 } 225 226 static void ad7879_timer(unsigned long handle) 227 { 228 struct ad7879 *ts = (void *)handle; 229 230 ad7879_ts_event_release(ts); 231 } 232 233 static irqreturn_t ad7879_irq(int irq, void *handle) 234 { 235 struct ad7879 *ts = handle; 236 237 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data); 238 239 if (!ad7879_report(ts)) 240 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 241 242 return IRQ_HANDLED; 243 } 244 245 static void __ad7879_enable(struct ad7879 *ts) 246 { 247 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 248 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3); 249 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1); 250 251 enable_irq(ts->irq); 252 } 253 254 static void __ad7879_disable(struct ad7879 *ts) 255 { 256 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) | 257 AD7879_PM(AD7879_PM_SHUTDOWN); 258 disable_irq(ts->irq); 259 260 if (del_timer_sync(&ts->timer)) 261 ad7879_ts_event_release(ts); 262 263 ad7879_write(ts, AD7879_REG_CTRL2, reg); 264 } 265 266 267 static int ad7879_open(struct input_dev *input) 268 { 269 struct ad7879 *ts = input_get_drvdata(input); 270 271 /* protected by input->mutex */ 272 if (!ts->disabled && !ts->suspended) 273 __ad7879_enable(ts); 274 275 return 0; 276 } 277 278 static void ad7879_close(struct input_dev* input) 279 { 280 struct ad7879 *ts = input_get_drvdata(input); 281 282 /* protected by input->mutex */ 283 if (!ts->disabled && !ts->suspended) 284 __ad7879_disable(ts); 285 } 286 287 static int __maybe_unused ad7879_suspend(struct device *dev) 288 { 289 struct ad7879 *ts = dev_get_drvdata(dev); 290 291 mutex_lock(&ts->input->mutex); 292 293 if (!ts->suspended && !ts->disabled && ts->input->users) 294 __ad7879_disable(ts); 295 296 ts->suspended = true; 297 298 mutex_unlock(&ts->input->mutex); 299 300 return 0; 301 } 302 303 static int __maybe_unused ad7879_resume(struct device *dev) 304 { 305 struct ad7879 *ts = dev_get_drvdata(dev); 306 307 mutex_lock(&ts->input->mutex); 308 309 if (ts->suspended && !ts->disabled && ts->input->users) 310 __ad7879_enable(ts); 311 312 ts->suspended = false; 313 314 mutex_unlock(&ts->input->mutex); 315 316 return 0; 317 } 318 319 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume); 320 EXPORT_SYMBOL(ad7879_pm_ops); 321 322 static void ad7879_toggle(struct ad7879 *ts, bool disable) 323 { 324 mutex_lock(&ts->input->mutex); 325 326 if (!ts->suspended && ts->input->users != 0) { 327 328 if (disable) { 329 if (ts->disabled) 330 __ad7879_enable(ts); 331 } else { 332 if (!ts->disabled) 333 __ad7879_disable(ts); 334 } 335 } 336 337 ts->disabled = disable; 338 339 mutex_unlock(&ts->input->mutex); 340 } 341 342 static ssize_t ad7879_disable_show(struct device *dev, 343 struct device_attribute *attr, char *buf) 344 { 345 struct ad7879 *ts = dev_get_drvdata(dev); 346 347 return sprintf(buf, "%u\n", ts->disabled); 348 } 349 350 static ssize_t ad7879_disable_store(struct device *dev, 351 struct device_attribute *attr, 352 const char *buf, size_t count) 353 { 354 struct ad7879 *ts = dev_get_drvdata(dev); 355 unsigned int val; 356 int error; 357 358 error = kstrtouint(buf, 10, &val); 359 if (error) 360 return error; 361 362 ad7879_toggle(ts, val); 363 364 return count; 365 } 366 367 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); 368 369 static struct attribute *ad7879_attributes[] = { 370 &dev_attr_disable.attr, 371 NULL 372 }; 373 374 static const struct attribute_group ad7879_attr_group = { 375 .attrs = ad7879_attributes, 376 }; 377 378 #ifdef CONFIG_GPIOLIB 379 static int ad7879_gpio_direction_input(struct gpio_chip *chip, 380 unsigned gpio) 381 { 382 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 383 int err; 384 385 mutex_lock(&ts->mutex); 386 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL; 387 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 388 mutex_unlock(&ts->mutex); 389 390 return err; 391 } 392 393 static int ad7879_gpio_direction_output(struct gpio_chip *chip, 394 unsigned gpio, int level) 395 { 396 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 397 int err; 398 399 mutex_lock(&ts->mutex); 400 ts->cmd_crtl2 &= ~AD7879_GPIODIR; 401 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL; 402 if (level) 403 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 404 else 405 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 406 407 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 408 mutex_unlock(&ts->mutex); 409 410 return err; 411 } 412 413 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio) 414 { 415 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 416 u16 val; 417 418 mutex_lock(&ts->mutex); 419 val = ad7879_read(ts, AD7879_REG_CTRL2); 420 mutex_unlock(&ts->mutex); 421 422 return !!(val & AD7879_GPIO_DATA); 423 } 424 425 static void ad7879_gpio_set_value(struct gpio_chip *chip, 426 unsigned gpio, int value) 427 { 428 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 429 430 mutex_lock(&ts->mutex); 431 if (value) 432 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 433 else 434 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 435 436 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 437 mutex_unlock(&ts->mutex); 438 } 439 440 static int ad7879_gpio_add(struct ad7879 *ts, 441 const struct ad7879_platform_data *pdata) 442 { 443 int ret = 0; 444 445 mutex_init(&ts->mutex); 446 447 if (pdata->gpio_export) { 448 ts->gc.direction_input = ad7879_gpio_direction_input; 449 ts->gc.direction_output = ad7879_gpio_direction_output; 450 ts->gc.get = ad7879_gpio_get_value; 451 ts->gc.set = ad7879_gpio_set_value; 452 ts->gc.can_sleep = 1; 453 ts->gc.base = pdata->gpio_base; 454 ts->gc.ngpio = 1; 455 ts->gc.label = "AD7879-GPIO"; 456 ts->gc.owner = THIS_MODULE; 457 ts->gc.dev = ts->dev; 458 459 ret = gpiochip_add(&ts->gc); 460 if (ret) 461 dev_err(ts->dev, "failed to register gpio %d\n", 462 ts->gc.base); 463 } 464 465 return ret; 466 } 467 468 static void ad7879_gpio_remove(struct ad7879 *ts) 469 { 470 const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev); 471 472 if (pdata->gpio_export) 473 gpiochip_remove(&ts->gc); 474 475 } 476 #else 477 static inline int ad7879_gpio_add(struct ad7879 *ts, 478 const struct ad7879_platform_data *pdata) 479 { 480 return 0; 481 } 482 483 static inline void ad7879_gpio_remove(struct ad7879 *ts) 484 { 485 } 486 #endif 487 488 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq, 489 const struct ad7879_bus_ops *bops) 490 { 491 struct ad7879_platform_data *pdata = dev_get_platdata(dev); 492 struct ad7879 *ts; 493 struct input_dev *input_dev; 494 int err; 495 u16 revid; 496 497 if (!irq) { 498 dev_err(dev, "no IRQ?\n"); 499 err = -EINVAL; 500 goto err_out; 501 } 502 503 if (!pdata) { 504 dev_err(dev, "no platform data?\n"); 505 err = -EINVAL; 506 goto err_out; 507 } 508 509 ts = kzalloc(sizeof(*ts), GFP_KERNEL); 510 input_dev = input_allocate_device(); 511 if (!ts || !input_dev) { 512 err = -ENOMEM; 513 goto err_free_mem; 514 } 515 516 ts->bops = bops; 517 ts->dev = dev; 518 ts->input = input_dev; 519 ts->irq = irq; 520 ts->swap_xy = pdata->swap_xy; 521 522 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); 523 524 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 525 ts->pressure_max = pdata->pressure_max ? : ~0; 526 527 ts->first_conversion_delay = pdata->first_conversion_delay; 528 ts->acquisition_time = pdata->acquisition_time; 529 ts->averaging = pdata->averaging; 530 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 531 ts->median = pdata->median; 532 533 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 534 535 input_dev->name = "AD7879 Touchscreen"; 536 input_dev->phys = ts->phys; 537 input_dev->dev.parent = dev; 538 input_dev->id.bustype = bops->bustype; 539 540 input_dev->open = ad7879_open; 541 input_dev->close = ad7879_close; 542 543 input_set_drvdata(input_dev, ts); 544 545 __set_bit(EV_ABS, input_dev->evbit); 546 __set_bit(ABS_X, input_dev->absbit); 547 __set_bit(ABS_Y, input_dev->absbit); 548 __set_bit(ABS_PRESSURE, input_dev->absbit); 549 550 __set_bit(EV_KEY, input_dev->evbit); 551 __set_bit(BTN_TOUCH, input_dev->keybit); 552 553 input_set_abs_params(input_dev, ABS_X, 554 pdata->x_min ? : 0, 555 pdata->x_max ? : MAX_12BIT, 556 0, 0); 557 input_set_abs_params(input_dev, ABS_Y, 558 pdata->y_min ? : 0, 559 pdata->y_max ? : MAX_12BIT, 560 0, 0); 561 input_set_abs_params(input_dev, ABS_PRESSURE, 562 pdata->pressure_min, pdata->pressure_max, 0, 0); 563 564 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET); 565 if (err < 0) { 566 dev_err(dev, "Failed to write %s\n", input_dev->name); 567 goto err_free_mem; 568 } 569 570 revid = ad7879_read(ts, AD7879_REG_REVID); 571 input_dev->id.product = (revid & 0xff); 572 input_dev->id.version = revid >> 8; 573 if (input_dev->id.product != devid) { 574 dev_err(dev, "Failed to probe %s (%x vs %x)\n", 575 input_dev->name, devid, revid); 576 err = -ENODEV; 577 goto err_free_mem; 578 } 579 580 ts->cmd_crtl3 = AD7879_YPLUS_BIT | 581 AD7879_XPLUS_BIT | 582 AD7879_Z2_BIT | 583 AD7879_Z1_BIT | 584 AD7879_TEMPMASK_BIT | 585 AD7879_AUXVBATMASK_BIT | 586 AD7879_GPIOALERTMASK_BIT; 587 588 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | 589 AD7879_AVG(ts->averaging) | 590 AD7879_MFS(ts->median) | 591 AD7879_FCD(ts->first_conversion_delay); 592 593 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | 594 AD7879_ACQ(ts->acquisition_time) | 595 AD7879_TMR(ts->pen_down_acc_interval); 596 597 err = request_threaded_irq(ts->irq, NULL, ad7879_irq, 598 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 599 dev_name(dev), ts); 600 if (err) { 601 dev_err(dev, "irq %d busy?\n", ts->irq); 602 goto err_free_mem; 603 } 604 605 __ad7879_disable(ts); 606 607 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group); 608 if (err) 609 goto err_free_irq; 610 611 err = ad7879_gpio_add(ts, pdata); 612 if (err) 613 goto err_remove_attr; 614 615 err = input_register_device(input_dev); 616 if (err) 617 goto err_remove_gpio; 618 619 return ts; 620 621 err_remove_gpio: 622 ad7879_gpio_remove(ts); 623 err_remove_attr: 624 sysfs_remove_group(&dev->kobj, &ad7879_attr_group); 625 err_free_irq: 626 free_irq(ts->irq, ts); 627 err_free_mem: 628 input_free_device(input_dev); 629 kfree(ts); 630 err_out: 631 return ERR_PTR(err); 632 } 633 EXPORT_SYMBOL(ad7879_probe); 634 635 void ad7879_remove(struct ad7879 *ts) 636 { 637 ad7879_gpio_remove(ts); 638 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group); 639 free_irq(ts->irq, ts); 640 input_unregister_device(ts->input); 641 kfree(ts); 642 } 643 EXPORT_SYMBOL(ad7879_remove); 644 645 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 646 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); 647 MODULE_LICENSE("GPL"); 648