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 #ifdef CONFIG_PM_SLEEP 288 static int ad7879_suspend(struct device *dev) 289 { 290 struct ad7879 *ts = dev_get_drvdata(dev); 291 292 mutex_lock(&ts->input->mutex); 293 294 if (!ts->suspended && !ts->disabled && ts->input->users) 295 __ad7879_disable(ts); 296 297 ts->suspended = true; 298 299 mutex_unlock(&ts->input->mutex); 300 301 return 0; 302 } 303 304 static int ad7879_resume(struct device *dev) 305 { 306 struct ad7879 *ts = dev_get_drvdata(dev); 307 308 mutex_lock(&ts->input->mutex); 309 310 if (ts->suspended && !ts->disabled && ts->input->users) 311 __ad7879_enable(ts); 312 313 ts->suspended = false; 314 315 mutex_unlock(&ts->input->mutex); 316 317 return 0; 318 } 319 #endif 320 321 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume); 322 EXPORT_SYMBOL(ad7879_pm_ops); 323 324 static void ad7879_toggle(struct ad7879 *ts, bool disable) 325 { 326 mutex_lock(&ts->input->mutex); 327 328 if (!ts->suspended && ts->input->users != 0) { 329 330 if (disable) { 331 if (ts->disabled) 332 __ad7879_enable(ts); 333 } else { 334 if (!ts->disabled) 335 __ad7879_disable(ts); 336 } 337 } 338 339 ts->disabled = disable; 340 341 mutex_unlock(&ts->input->mutex); 342 } 343 344 static ssize_t ad7879_disable_show(struct device *dev, 345 struct device_attribute *attr, char *buf) 346 { 347 struct ad7879 *ts = dev_get_drvdata(dev); 348 349 return sprintf(buf, "%u\n", ts->disabled); 350 } 351 352 static ssize_t ad7879_disable_store(struct device *dev, 353 struct device_attribute *attr, 354 const char *buf, size_t count) 355 { 356 struct ad7879 *ts = dev_get_drvdata(dev); 357 unsigned int val; 358 int error; 359 360 error = kstrtouint(buf, 10, &val); 361 if (error) 362 return error; 363 364 ad7879_toggle(ts, val); 365 366 return count; 367 } 368 369 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); 370 371 static struct attribute *ad7879_attributes[] = { 372 &dev_attr_disable.attr, 373 NULL 374 }; 375 376 static const struct attribute_group ad7879_attr_group = { 377 .attrs = ad7879_attributes, 378 }; 379 380 #ifdef CONFIG_GPIOLIB 381 static int ad7879_gpio_direction_input(struct gpio_chip *chip, 382 unsigned gpio) 383 { 384 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 385 int err; 386 387 mutex_lock(&ts->mutex); 388 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL; 389 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 390 mutex_unlock(&ts->mutex); 391 392 return err; 393 } 394 395 static int ad7879_gpio_direction_output(struct gpio_chip *chip, 396 unsigned gpio, int level) 397 { 398 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 399 int err; 400 401 mutex_lock(&ts->mutex); 402 ts->cmd_crtl2 &= ~AD7879_GPIODIR; 403 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL; 404 if (level) 405 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 406 else 407 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 408 409 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 410 mutex_unlock(&ts->mutex); 411 412 return err; 413 } 414 415 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio) 416 { 417 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 418 u16 val; 419 420 mutex_lock(&ts->mutex); 421 val = ad7879_read(ts, AD7879_REG_CTRL2); 422 mutex_unlock(&ts->mutex); 423 424 return !!(val & AD7879_GPIO_DATA); 425 } 426 427 static void ad7879_gpio_set_value(struct gpio_chip *chip, 428 unsigned gpio, int value) 429 { 430 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 431 432 mutex_lock(&ts->mutex); 433 if (value) 434 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 435 else 436 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 437 438 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 439 mutex_unlock(&ts->mutex); 440 } 441 442 static int ad7879_gpio_add(struct ad7879 *ts, 443 const struct ad7879_platform_data *pdata) 444 { 445 int ret = 0; 446 447 mutex_init(&ts->mutex); 448 449 if (pdata->gpio_export) { 450 ts->gc.direction_input = ad7879_gpio_direction_input; 451 ts->gc.direction_output = ad7879_gpio_direction_output; 452 ts->gc.get = ad7879_gpio_get_value; 453 ts->gc.set = ad7879_gpio_set_value; 454 ts->gc.can_sleep = 1; 455 ts->gc.base = pdata->gpio_base; 456 ts->gc.ngpio = 1; 457 ts->gc.label = "AD7879-GPIO"; 458 ts->gc.owner = THIS_MODULE; 459 ts->gc.dev = ts->dev; 460 461 ret = gpiochip_add(&ts->gc); 462 if (ret) 463 dev_err(ts->dev, "failed to register gpio %d\n", 464 ts->gc.base); 465 } 466 467 return ret; 468 } 469 470 static void ad7879_gpio_remove(struct ad7879 *ts) 471 { 472 const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev); 473 int ret; 474 475 if (pdata->gpio_export) { 476 ret = gpiochip_remove(&ts->gc); 477 if (ret) 478 dev_err(ts->dev, "failed to remove gpio %d\n", 479 ts->gc.base); 480 } 481 } 482 #else 483 static inline int ad7879_gpio_add(struct ad7879 *ts, 484 const struct ad7879_platform_data *pdata) 485 { 486 return 0; 487 } 488 489 static inline void ad7879_gpio_remove(struct ad7879 *ts) 490 { 491 } 492 #endif 493 494 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq, 495 const struct ad7879_bus_ops *bops) 496 { 497 struct ad7879_platform_data *pdata = dev_get_platdata(dev); 498 struct ad7879 *ts; 499 struct input_dev *input_dev; 500 int err; 501 u16 revid; 502 503 if (!irq) { 504 dev_err(dev, "no IRQ?\n"); 505 err = -EINVAL; 506 goto err_out; 507 } 508 509 if (!pdata) { 510 dev_err(dev, "no platform data?\n"); 511 err = -EINVAL; 512 goto err_out; 513 } 514 515 ts = kzalloc(sizeof(*ts), GFP_KERNEL); 516 input_dev = input_allocate_device(); 517 if (!ts || !input_dev) { 518 err = -ENOMEM; 519 goto err_free_mem; 520 } 521 522 ts->bops = bops; 523 ts->dev = dev; 524 ts->input = input_dev; 525 ts->irq = irq; 526 ts->swap_xy = pdata->swap_xy; 527 528 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); 529 530 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 531 ts->pressure_max = pdata->pressure_max ? : ~0; 532 533 ts->first_conversion_delay = pdata->first_conversion_delay; 534 ts->acquisition_time = pdata->acquisition_time; 535 ts->averaging = pdata->averaging; 536 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 537 ts->median = pdata->median; 538 539 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 540 541 input_dev->name = "AD7879 Touchscreen"; 542 input_dev->phys = ts->phys; 543 input_dev->dev.parent = dev; 544 input_dev->id.bustype = bops->bustype; 545 546 input_dev->open = ad7879_open; 547 input_dev->close = ad7879_close; 548 549 input_set_drvdata(input_dev, ts); 550 551 __set_bit(EV_ABS, input_dev->evbit); 552 __set_bit(ABS_X, input_dev->absbit); 553 __set_bit(ABS_Y, input_dev->absbit); 554 __set_bit(ABS_PRESSURE, input_dev->absbit); 555 556 __set_bit(EV_KEY, input_dev->evbit); 557 __set_bit(BTN_TOUCH, input_dev->keybit); 558 559 input_set_abs_params(input_dev, ABS_X, 560 pdata->x_min ? : 0, 561 pdata->x_max ? : MAX_12BIT, 562 0, 0); 563 input_set_abs_params(input_dev, ABS_Y, 564 pdata->y_min ? : 0, 565 pdata->y_max ? : MAX_12BIT, 566 0, 0); 567 input_set_abs_params(input_dev, ABS_PRESSURE, 568 pdata->pressure_min, pdata->pressure_max, 0, 0); 569 570 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET); 571 if (err < 0) { 572 dev_err(dev, "Failed to write %s\n", input_dev->name); 573 goto err_free_mem; 574 } 575 576 revid = ad7879_read(ts, AD7879_REG_REVID); 577 input_dev->id.product = (revid & 0xff); 578 input_dev->id.version = revid >> 8; 579 if (input_dev->id.product != devid) { 580 dev_err(dev, "Failed to probe %s (%x vs %x)\n", 581 input_dev->name, devid, revid); 582 err = -ENODEV; 583 goto err_free_mem; 584 } 585 586 ts->cmd_crtl3 = AD7879_YPLUS_BIT | 587 AD7879_XPLUS_BIT | 588 AD7879_Z2_BIT | 589 AD7879_Z1_BIT | 590 AD7879_TEMPMASK_BIT | 591 AD7879_AUXVBATMASK_BIT | 592 AD7879_GPIOALERTMASK_BIT; 593 594 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | 595 AD7879_AVG(ts->averaging) | 596 AD7879_MFS(ts->median) | 597 AD7879_FCD(ts->first_conversion_delay); 598 599 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | 600 AD7879_ACQ(ts->acquisition_time) | 601 AD7879_TMR(ts->pen_down_acc_interval); 602 603 err = request_threaded_irq(ts->irq, NULL, ad7879_irq, 604 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 605 dev_name(dev), ts); 606 if (err) { 607 dev_err(dev, "irq %d busy?\n", ts->irq); 608 goto err_free_mem; 609 } 610 611 __ad7879_disable(ts); 612 613 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group); 614 if (err) 615 goto err_free_irq; 616 617 err = ad7879_gpio_add(ts, pdata); 618 if (err) 619 goto err_remove_attr; 620 621 err = input_register_device(input_dev); 622 if (err) 623 goto err_remove_gpio; 624 625 return ts; 626 627 err_remove_gpio: 628 ad7879_gpio_remove(ts); 629 err_remove_attr: 630 sysfs_remove_group(&dev->kobj, &ad7879_attr_group); 631 err_free_irq: 632 free_irq(ts->irq, ts); 633 err_free_mem: 634 input_free_device(input_dev); 635 kfree(ts); 636 err_out: 637 return ERR_PTR(err); 638 } 639 EXPORT_SYMBOL(ad7879_probe); 640 641 void ad7879_remove(struct ad7879 *ts) 642 { 643 ad7879_gpio_remove(ts); 644 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group); 645 free_irq(ts->irq, ts); 646 input_unregister_device(ts->input); 647 kfree(ts); 648 } 649 EXPORT_SYMBOL(ad7879_remove); 650 651 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 652 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); 653 MODULE_LICENSE("GPL"); 654