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/init.h> 26 #include <linux/delay.h> 27 #include <linux/input.h> 28 #include <linux/interrupt.h> 29 #include <linux/irq.h> 30 #include <linux/slab.h> 31 #include <linux/spi/spi.h> 32 #include <linux/i2c.h> 33 #include <linux/gpio.h> 34 35 #include <linux/spi/ad7879.h> 36 #include <linux/module.h> 37 #include "ad7879.h" 38 39 #define AD7879_REG_ZEROS 0 40 #define AD7879_REG_CTRL1 1 41 #define AD7879_REG_CTRL2 2 42 #define AD7879_REG_CTRL3 3 43 #define AD7879_REG_AUX1HIGH 4 44 #define AD7879_REG_AUX1LOW 5 45 #define AD7879_REG_TEMP1HIGH 6 46 #define AD7879_REG_TEMP1LOW 7 47 #define AD7879_REG_XPLUS 8 48 #define AD7879_REG_YPLUS 9 49 #define AD7879_REG_Z1 10 50 #define AD7879_REG_Z2 11 51 #define AD7879_REG_AUXVBAT 12 52 #define AD7879_REG_TEMP 13 53 #define AD7879_REG_REVID 14 54 55 /* Control REG 1 */ 56 #define AD7879_TMR(x) ((x & 0xFF) << 0) 57 #define AD7879_ACQ(x) ((x & 0x3) << 8) 58 #define AD7879_MODE_NOC (0 << 10) /* Do not convert */ 59 #define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */ 60 #define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */ 61 #define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */ 62 #define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */ 63 64 /* Control REG 2 */ 65 #define AD7879_FCD(x) ((x & 0x3) << 0) 66 #define AD7879_RESET (1 << 4) 67 #define AD7879_MFS(x) ((x & 0x3) << 5) 68 #define AD7879_AVG(x) ((x & 0x3) << 7) 69 #define AD7879_SER (1 << 9) /* non-differential */ 70 #define AD7879_DFR (0 << 9) /* differential */ 71 #define AD7879_GPIOPOL (1 << 10) 72 #define AD7879_GPIODIR (1 << 11) 73 #define AD7879_GPIO_DATA (1 << 12) 74 #define AD7879_GPIO_EN (1 << 13) 75 #define AD7879_PM(x) ((x & 0x3) << 14) 76 #define AD7879_PM_SHUTDOWN (0) 77 #define AD7879_PM_DYN (1) 78 #define AD7879_PM_FULLON (2) 79 80 /* Control REG 3 */ 81 #define AD7879_TEMPMASK_BIT (1<<15) 82 #define AD7879_AUXVBATMASK_BIT (1<<14) 83 #define AD7879_INTMODE_BIT (1<<13) 84 #define AD7879_GPIOALERTMASK_BIT (1<<12) 85 #define AD7879_AUXLOW_BIT (1<<11) 86 #define AD7879_AUXHIGH_BIT (1<<10) 87 #define AD7879_TEMPLOW_BIT (1<<9) 88 #define AD7879_TEMPHIGH_BIT (1<<8) 89 #define AD7879_YPLUS_BIT (1<<7) 90 #define AD7879_XPLUS_BIT (1<<6) 91 #define AD7879_Z1_BIT (1<<5) 92 #define AD7879_Z2_BIT (1<<4) 93 #define AD7879_AUX_BIT (1<<3) 94 #define AD7879_VBAT_BIT (1<<2) 95 #define AD7879_TEMP_BIT (1<<1) 96 97 enum { 98 AD7879_SEQ_XPOS = 0, 99 AD7879_SEQ_YPOS = 1, 100 AD7879_SEQ_Z1 = 2, 101 AD7879_SEQ_Z2 = 3, 102 AD7879_NR_SENSE = 4, 103 }; 104 105 #define MAX_12BIT ((1<<12)-1) 106 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50) 107 108 struct ad7879 { 109 const struct ad7879_bus_ops *bops; 110 111 struct device *dev; 112 struct input_dev *input; 113 struct timer_list timer; 114 #ifdef CONFIG_GPIOLIB 115 struct gpio_chip gc; 116 struct mutex mutex; 117 #endif 118 unsigned int irq; 119 bool disabled; /* P: input->mutex */ 120 bool suspended; /* P: input->mutex */ 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 /* 165 * The samples processed here are already preprocessed by the AD7879. 166 * The preprocessing function consists of a median and an averaging 167 * filter. The combination of these two techniques provides a robust 168 * solution, discarding the spurious noise in the signal and keeping 169 * only the data of interest. The size of both filters is 170 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other 171 * user-programmable conversion controls include variable acquisition 172 * time, and first conversion delay. Up to 16 averages can be taken 173 * per conversion. 174 */ 175 176 if (likely(x && z1)) { 177 /* compute touch pressure resistance using equation #1 */ 178 Rt = (z2 - z1) * x * ts->x_plate_ohms; 179 Rt /= z1; 180 Rt = (Rt + 2047) >> 12; 181 182 /* 183 * Sample found inconsistent, pressure is beyond 184 * the maximum. Don't report it to user space. 185 */ 186 if (Rt > ts->pressure_max) 187 return -EINVAL; 188 189 /* 190 * Note that we delay reporting events by one sample. 191 * This is done to avoid reporting last sample of the 192 * touch sequence, which may be incomplete if finger 193 * leaves the surface before last reading is taken. 194 */ 195 if (timer_pending(&ts->timer)) { 196 /* Touch continues */ 197 input_report_key(input_dev, BTN_TOUCH, 1); 198 input_report_abs(input_dev, ABS_X, ts->x); 199 input_report_abs(input_dev, ABS_Y, ts->y); 200 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt); 201 input_sync(input_dev); 202 } 203 204 ts->x = x; 205 ts->y = y; 206 ts->Rt = Rt; 207 208 return 0; 209 } 210 211 return -EINVAL; 212 } 213 214 static void ad7879_ts_event_release(struct ad7879 *ts) 215 { 216 struct input_dev *input_dev = ts->input; 217 218 input_report_abs(input_dev, ABS_PRESSURE, 0); 219 input_report_key(input_dev, BTN_TOUCH, 0); 220 input_sync(input_dev); 221 } 222 223 static void ad7879_timer(unsigned long handle) 224 { 225 struct ad7879 *ts = (void *)handle; 226 227 ad7879_ts_event_release(ts); 228 } 229 230 static irqreturn_t ad7879_irq(int irq, void *handle) 231 { 232 struct ad7879 *ts = handle; 233 234 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data); 235 236 if (!ad7879_report(ts)) 237 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 238 239 return IRQ_HANDLED; 240 } 241 242 static void __ad7879_enable(struct ad7879 *ts) 243 { 244 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 245 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3); 246 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1); 247 248 enable_irq(ts->irq); 249 } 250 251 static void __ad7879_disable(struct ad7879 *ts) 252 { 253 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) | 254 AD7879_PM(AD7879_PM_SHUTDOWN); 255 disable_irq(ts->irq); 256 257 if (del_timer_sync(&ts->timer)) 258 ad7879_ts_event_release(ts); 259 260 ad7879_write(ts, AD7879_REG_CTRL2, reg); 261 } 262 263 264 static int ad7879_open(struct input_dev *input) 265 { 266 struct ad7879 *ts = input_get_drvdata(input); 267 268 /* protected by input->mutex */ 269 if (!ts->disabled && !ts->suspended) 270 __ad7879_enable(ts); 271 272 return 0; 273 } 274 275 static void ad7879_close(struct input_dev* input) 276 { 277 struct ad7879 *ts = input_get_drvdata(input); 278 279 /* protected by input->mutex */ 280 if (!ts->disabled && !ts->suspended) 281 __ad7879_disable(ts); 282 } 283 284 #ifdef CONFIG_PM_SLEEP 285 static int ad7879_suspend(struct device *dev) 286 { 287 struct ad7879 *ts = dev_get_drvdata(dev); 288 289 mutex_lock(&ts->input->mutex); 290 291 if (!ts->suspended && !ts->disabled && ts->input->users) 292 __ad7879_disable(ts); 293 294 ts->suspended = true; 295 296 mutex_unlock(&ts->input->mutex); 297 298 return 0; 299 } 300 301 static int ad7879_resume(struct device *dev) 302 { 303 struct ad7879 *ts = dev_get_drvdata(dev); 304 305 mutex_lock(&ts->input->mutex); 306 307 if (ts->suspended && !ts->disabled && ts->input->users) 308 __ad7879_enable(ts); 309 310 ts->suspended = false; 311 312 mutex_unlock(&ts->input->mutex); 313 314 return 0; 315 } 316 #endif 317 318 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume); 319 EXPORT_SYMBOL(ad7879_pm_ops); 320 321 static void ad7879_toggle(struct ad7879 *ts, bool disable) 322 { 323 mutex_lock(&ts->input->mutex); 324 325 if (!ts->suspended && ts->input->users != 0) { 326 327 if (disable) { 328 if (ts->disabled) 329 __ad7879_enable(ts); 330 } else { 331 if (!ts->disabled) 332 __ad7879_disable(ts); 333 } 334 } 335 336 ts->disabled = disable; 337 338 mutex_unlock(&ts->input->mutex); 339 } 340 341 static ssize_t ad7879_disable_show(struct device *dev, 342 struct device_attribute *attr, char *buf) 343 { 344 struct ad7879 *ts = dev_get_drvdata(dev); 345 346 return sprintf(buf, "%u\n", ts->disabled); 347 } 348 349 static ssize_t ad7879_disable_store(struct device *dev, 350 struct device_attribute *attr, 351 const char *buf, size_t count) 352 { 353 struct ad7879 *ts = dev_get_drvdata(dev); 354 unsigned int val; 355 int error; 356 357 error = kstrtouint(buf, 10, &val); 358 if (error) 359 return error; 360 361 ad7879_toggle(ts, val); 362 363 return count; 364 } 365 366 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); 367 368 static struct attribute *ad7879_attributes[] = { 369 &dev_attr_disable.attr, 370 NULL 371 }; 372 373 static const struct attribute_group ad7879_attr_group = { 374 .attrs = ad7879_attributes, 375 }; 376 377 #ifdef CONFIG_GPIOLIB 378 static int ad7879_gpio_direction_input(struct gpio_chip *chip, 379 unsigned gpio) 380 { 381 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 382 int err; 383 384 mutex_lock(&ts->mutex); 385 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL; 386 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 387 mutex_unlock(&ts->mutex); 388 389 return err; 390 } 391 392 static int ad7879_gpio_direction_output(struct gpio_chip *chip, 393 unsigned gpio, int level) 394 { 395 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 396 int err; 397 398 mutex_lock(&ts->mutex); 399 ts->cmd_crtl2 &= ~AD7879_GPIODIR; 400 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL; 401 if (level) 402 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 403 else 404 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 405 406 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 407 mutex_unlock(&ts->mutex); 408 409 return err; 410 } 411 412 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio) 413 { 414 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 415 u16 val; 416 417 mutex_lock(&ts->mutex); 418 val = ad7879_read(ts, AD7879_REG_CTRL2); 419 mutex_unlock(&ts->mutex); 420 421 return !!(val & AD7879_GPIO_DATA); 422 } 423 424 static void ad7879_gpio_set_value(struct gpio_chip *chip, 425 unsigned gpio, int value) 426 { 427 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 428 429 mutex_lock(&ts->mutex); 430 if (value) 431 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 432 else 433 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 434 435 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 436 mutex_unlock(&ts->mutex); 437 } 438 439 static int ad7879_gpio_add(struct ad7879 *ts, 440 const struct ad7879_platform_data *pdata) 441 { 442 int ret = 0; 443 444 mutex_init(&ts->mutex); 445 446 if (pdata->gpio_export) { 447 ts->gc.direction_input = ad7879_gpio_direction_input; 448 ts->gc.direction_output = ad7879_gpio_direction_output; 449 ts->gc.get = ad7879_gpio_get_value; 450 ts->gc.set = ad7879_gpio_set_value; 451 ts->gc.can_sleep = 1; 452 ts->gc.base = pdata->gpio_base; 453 ts->gc.ngpio = 1; 454 ts->gc.label = "AD7879-GPIO"; 455 ts->gc.owner = THIS_MODULE; 456 ts->gc.dev = ts->dev; 457 458 ret = gpiochip_add(&ts->gc); 459 if (ret) 460 dev_err(ts->dev, "failed to register gpio %d\n", 461 ts->gc.base); 462 } 463 464 return ret; 465 } 466 467 static void ad7879_gpio_remove(struct ad7879 *ts) 468 { 469 const struct ad7879_platform_data *pdata = ts->dev->platform_data; 470 int ret; 471 472 if (pdata->gpio_export) { 473 ret = gpiochip_remove(&ts->gc); 474 if (ret) 475 dev_err(ts->dev, "failed to remove gpio %d\n", 476 ts->gc.base); 477 } 478 } 479 #else 480 static inline int ad7879_gpio_add(struct ad7879 *ts, 481 const struct ad7879_platform_data *pdata) 482 { 483 return 0; 484 } 485 486 static inline void ad7879_gpio_remove(struct ad7879 *ts) 487 { 488 } 489 #endif 490 491 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq, 492 const struct ad7879_bus_ops *bops) 493 { 494 struct ad7879_platform_data *pdata = dev->platform_data; 495 struct ad7879 *ts; 496 struct input_dev *input_dev; 497 int err; 498 u16 revid; 499 500 if (!irq) { 501 dev_err(dev, "no IRQ?\n"); 502 err = -EINVAL; 503 goto err_out; 504 } 505 506 if (!pdata) { 507 dev_err(dev, "no platform data?\n"); 508 err = -EINVAL; 509 goto err_out; 510 } 511 512 ts = kzalloc(sizeof(*ts), GFP_KERNEL); 513 input_dev = input_allocate_device(); 514 if (!ts || !input_dev) { 515 err = -ENOMEM; 516 goto err_free_mem; 517 } 518 519 ts->bops = bops; 520 ts->dev = dev; 521 ts->input = input_dev; 522 ts->irq = irq; 523 524 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); 525 526 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 527 ts->pressure_max = pdata->pressure_max ? : ~0; 528 529 ts->first_conversion_delay = pdata->first_conversion_delay; 530 ts->acquisition_time = pdata->acquisition_time; 531 ts->averaging = pdata->averaging; 532 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 533 ts->median = pdata->median; 534 535 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 536 537 input_dev->name = "AD7879 Touchscreen"; 538 input_dev->phys = ts->phys; 539 input_dev->dev.parent = dev; 540 input_dev->id.bustype = bops->bustype; 541 542 input_dev->open = ad7879_open; 543 input_dev->close = ad7879_close; 544 545 input_set_drvdata(input_dev, ts); 546 547 __set_bit(EV_ABS, input_dev->evbit); 548 __set_bit(ABS_X, input_dev->absbit); 549 __set_bit(ABS_Y, input_dev->absbit); 550 __set_bit(ABS_PRESSURE, input_dev->absbit); 551 552 __set_bit(EV_KEY, input_dev->evbit); 553 __set_bit(BTN_TOUCH, input_dev->keybit); 554 555 input_set_abs_params(input_dev, ABS_X, 556 pdata->x_min ? : 0, 557 pdata->x_max ? : MAX_12BIT, 558 0, 0); 559 input_set_abs_params(input_dev, ABS_Y, 560 pdata->y_min ? : 0, 561 pdata->y_max ? : MAX_12BIT, 562 0, 0); 563 input_set_abs_params(input_dev, ABS_PRESSURE, 564 pdata->pressure_min, pdata->pressure_max, 0, 0); 565 566 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET); 567 if (err < 0) { 568 dev_err(dev, "Failed to write %s\n", input_dev->name); 569 goto err_free_mem; 570 } 571 572 revid = ad7879_read(ts, AD7879_REG_REVID); 573 input_dev->id.product = (revid & 0xff); 574 input_dev->id.version = revid >> 8; 575 if (input_dev->id.product != devid) { 576 dev_err(dev, "Failed to probe %s (%x vs %x)\n", 577 input_dev->name, devid, revid); 578 err = -ENODEV; 579 goto err_free_mem; 580 } 581 582 ts->cmd_crtl3 = AD7879_YPLUS_BIT | 583 AD7879_XPLUS_BIT | 584 AD7879_Z2_BIT | 585 AD7879_Z1_BIT | 586 AD7879_TEMPMASK_BIT | 587 AD7879_AUXVBATMASK_BIT | 588 AD7879_GPIOALERTMASK_BIT; 589 590 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | 591 AD7879_AVG(ts->averaging) | 592 AD7879_MFS(ts->median) | 593 AD7879_FCD(ts->first_conversion_delay); 594 595 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | 596 AD7879_ACQ(ts->acquisition_time) | 597 AD7879_TMR(ts->pen_down_acc_interval); 598 599 err = request_threaded_irq(ts->irq, NULL, ad7879_irq, 600 IRQF_TRIGGER_FALLING, 601 dev_name(dev), ts); 602 if (err) { 603 dev_err(dev, "irq %d busy?\n", ts->irq); 604 goto err_free_mem; 605 } 606 607 __ad7879_disable(ts); 608 609 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group); 610 if (err) 611 goto err_free_irq; 612 613 err = ad7879_gpio_add(ts, pdata); 614 if (err) 615 goto err_remove_attr; 616 617 err = input_register_device(input_dev); 618 if (err) 619 goto err_remove_gpio; 620 621 return ts; 622 623 err_remove_gpio: 624 ad7879_gpio_remove(ts); 625 err_remove_attr: 626 sysfs_remove_group(&dev->kobj, &ad7879_attr_group); 627 err_free_irq: 628 free_irq(ts->irq, ts); 629 err_free_mem: 630 input_free_device(input_dev); 631 kfree(ts); 632 err_out: 633 return ERR_PTR(err); 634 } 635 EXPORT_SYMBOL(ad7879_probe); 636 637 void ad7879_remove(struct ad7879 *ts) 638 { 639 ad7879_gpio_remove(ts); 640 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group); 641 free_irq(ts->irq, ts); 642 input_unregister_device(ts->input); 643 kfree(ts); 644 } 645 EXPORT_SYMBOL(ad7879_remove); 646 647 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 648 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); 649 MODULE_LICENSE("GPL"); 650