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 "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 u16 conversion_data[AD7879_NR_SENSE]; 121 char phys[32]; 122 u8 first_conversion_delay; 123 u8 acquisition_time; 124 u8 averaging; 125 u8 pen_down_acc_interval; 126 u8 median; 127 u16 x_plate_ohms; 128 u16 pressure_max; 129 u16 cmd_crtl1; 130 u16 cmd_crtl2; 131 u16 cmd_crtl3; 132 int x; 133 int y; 134 int Rt; 135 }; 136 137 static int ad7879_read(struct ad7879 *ts, u8 reg) 138 { 139 return ts->bops->read(ts->dev, reg); 140 } 141 142 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf) 143 { 144 return ts->bops->multi_read(ts->dev, first_reg, count, buf); 145 } 146 147 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val) 148 { 149 return ts->bops->write(ts->dev, reg, val); 150 } 151 152 static int ad7879_report(struct ad7879 *ts) 153 { 154 struct input_dev *input_dev = ts->input; 155 unsigned Rt; 156 u16 x, y, z1, z2; 157 158 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT; 159 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT; 160 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT; 161 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT; 162 163 /* 164 * The samples processed here are already preprocessed by the AD7879. 165 * The preprocessing function consists of a median and an averaging 166 * filter. The combination of these two techniques provides a robust 167 * solution, discarding the spurious noise in the signal and keeping 168 * only the data of interest. The size of both filters is 169 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other 170 * user-programmable conversion controls include variable acquisition 171 * time, and first conversion delay. Up to 16 averages can be taken 172 * per conversion. 173 */ 174 175 if (likely(x && z1)) { 176 /* compute touch pressure resistance using equation #1 */ 177 Rt = (z2 - z1) * x * ts->x_plate_ohms; 178 Rt /= z1; 179 Rt = (Rt + 2047) >> 12; 180 181 /* 182 * Sample found inconsistent, pressure is beyond 183 * the maximum. Don't report it to user space. 184 */ 185 if (Rt > ts->pressure_max) 186 return -EINVAL; 187 188 /* 189 * Note that we delay reporting events by one sample. 190 * This is done to avoid reporting last sample of the 191 * touch sequence, which may be incomplete if finger 192 * leaves the surface before last reading is taken. 193 */ 194 if (timer_pending(&ts->timer)) { 195 /* Touch continues */ 196 input_report_key(input_dev, BTN_TOUCH, 1); 197 input_report_abs(input_dev, ABS_X, ts->x); 198 input_report_abs(input_dev, ABS_Y, ts->y); 199 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt); 200 input_sync(input_dev); 201 } 202 203 ts->x = x; 204 ts->y = y; 205 ts->Rt = Rt; 206 207 return 0; 208 } 209 210 return -EINVAL; 211 } 212 213 static void ad7879_ts_event_release(struct ad7879 *ts) 214 { 215 struct input_dev *input_dev = ts->input; 216 217 input_report_abs(input_dev, ABS_PRESSURE, 0); 218 input_report_key(input_dev, BTN_TOUCH, 0); 219 input_sync(input_dev); 220 } 221 222 static void ad7879_timer(unsigned long handle) 223 { 224 struct ad7879 *ts = (void *)handle; 225 226 ad7879_ts_event_release(ts); 227 } 228 229 static irqreturn_t ad7879_irq(int irq, void *handle) 230 { 231 struct ad7879 *ts = handle; 232 233 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data); 234 235 if (!ad7879_report(ts)) 236 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 237 238 return IRQ_HANDLED; 239 } 240 241 static void __ad7879_enable(struct ad7879 *ts) 242 { 243 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 244 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3); 245 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1); 246 247 enable_irq(ts->irq); 248 } 249 250 static void __ad7879_disable(struct ad7879 *ts) 251 { 252 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) | 253 AD7879_PM(AD7879_PM_SHUTDOWN); 254 disable_irq(ts->irq); 255 256 if (del_timer_sync(&ts->timer)) 257 ad7879_ts_event_release(ts); 258 259 ad7879_write(ts, AD7879_REG_CTRL2, reg); 260 } 261 262 263 static int ad7879_open(struct input_dev *input) 264 { 265 struct ad7879 *ts = input_get_drvdata(input); 266 267 /* protected by input->mutex */ 268 if (!ts->disabled && !ts->suspended) 269 __ad7879_enable(ts); 270 271 return 0; 272 } 273 274 static void ad7879_close(struct input_dev* input) 275 { 276 struct ad7879 *ts = input_get_drvdata(input); 277 278 /* protected by input->mutex */ 279 if (!ts->disabled && !ts->suspended) 280 __ad7879_disable(ts); 281 } 282 283 void ad7879_suspend(struct ad7879 *ts) 284 { 285 mutex_lock(&ts->input->mutex); 286 287 if (!ts->suspended && !ts->disabled && ts->input->users) 288 __ad7879_disable(ts); 289 290 ts->suspended = true; 291 292 mutex_unlock(&ts->input->mutex); 293 } 294 EXPORT_SYMBOL(ad7879_suspend); 295 296 void ad7879_resume(struct ad7879 *ts) 297 { 298 mutex_lock(&ts->input->mutex); 299 300 if (ts->suspended && !ts->disabled && ts->input->users) 301 __ad7879_enable(ts); 302 303 ts->suspended = false; 304 305 mutex_unlock(&ts->input->mutex); 306 } 307 EXPORT_SYMBOL(ad7879_resume); 308 309 static void ad7879_toggle(struct ad7879 *ts, bool disable) 310 { 311 mutex_lock(&ts->input->mutex); 312 313 if (!ts->suspended && ts->input->users != 0) { 314 315 if (disable) { 316 if (ts->disabled) 317 __ad7879_enable(ts); 318 } else { 319 if (!ts->disabled) 320 __ad7879_disable(ts); 321 } 322 } 323 324 ts->disabled = disable; 325 326 mutex_unlock(&ts->input->mutex); 327 } 328 329 static ssize_t ad7879_disable_show(struct device *dev, 330 struct device_attribute *attr, char *buf) 331 { 332 struct ad7879 *ts = dev_get_drvdata(dev); 333 334 return sprintf(buf, "%u\n", ts->disabled); 335 } 336 337 static ssize_t ad7879_disable_store(struct device *dev, 338 struct device_attribute *attr, 339 const char *buf, size_t count) 340 { 341 struct ad7879 *ts = dev_get_drvdata(dev); 342 unsigned long val; 343 int error; 344 345 error = strict_strtoul(buf, 10, &val); 346 if (error) 347 return error; 348 349 ad7879_toggle(ts, val); 350 351 return count; 352 } 353 354 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); 355 356 static struct attribute *ad7879_attributes[] = { 357 &dev_attr_disable.attr, 358 NULL 359 }; 360 361 static const struct attribute_group ad7879_attr_group = { 362 .attrs = ad7879_attributes, 363 }; 364 365 #ifdef CONFIG_GPIOLIB 366 static int ad7879_gpio_direction_input(struct gpio_chip *chip, 367 unsigned gpio) 368 { 369 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 370 int err; 371 372 mutex_lock(&ts->mutex); 373 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL; 374 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 375 mutex_unlock(&ts->mutex); 376 377 return err; 378 } 379 380 static int ad7879_gpio_direction_output(struct gpio_chip *chip, 381 unsigned gpio, int level) 382 { 383 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 384 int err; 385 386 mutex_lock(&ts->mutex); 387 ts->cmd_crtl2 &= ~AD7879_GPIODIR; 388 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL; 389 if (level) 390 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 391 else 392 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 393 394 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 395 mutex_unlock(&ts->mutex); 396 397 return err; 398 } 399 400 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio) 401 { 402 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 403 u16 val; 404 405 mutex_lock(&ts->mutex); 406 val = ad7879_read(ts, AD7879_REG_CTRL2); 407 mutex_unlock(&ts->mutex); 408 409 return !!(val & AD7879_GPIO_DATA); 410 } 411 412 static void ad7879_gpio_set_value(struct gpio_chip *chip, 413 unsigned gpio, int value) 414 { 415 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 416 417 mutex_lock(&ts->mutex); 418 if (value) 419 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 420 else 421 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 422 423 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 424 mutex_unlock(&ts->mutex); 425 } 426 427 static int ad7879_gpio_add(struct ad7879 *ts, 428 const struct ad7879_platform_data *pdata) 429 { 430 int ret = 0; 431 432 mutex_init(&ts->mutex); 433 434 if (pdata->gpio_export) { 435 ts->gc.direction_input = ad7879_gpio_direction_input; 436 ts->gc.direction_output = ad7879_gpio_direction_output; 437 ts->gc.get = ad7879_gpio_get_value; 438 ts->gc.set = ad7879_gpio_set_value; 439 ts->gc.can_sleep = 1; 440 ts->gc.base = pdata->gpio_base; 441 ts->gc.ngpio = 1; 442 ts->gc.label = "AD7879-GPIO"; 443 ts->gc.owner = THIS_MODULE; 444 ts->gc.dev = ts->dev; 445 446 ret = gpiochip_add(&ts->gc); 447 if (ret) 448 dev_err(ts->dev, "failed to register gpio %d\n", 449 ts->gc.base); 450 } 451 452 return ret; 453 } 454 455 static void ad7879_gpio_remove(struct ad7879 *ts) 456 { 457 const struct ad7879_platform_data *pdata = ts->dev->platform_data; 458 int ret; 459 460 if (pdata->gpio_export) { 461 ret = gpiochip_remove(&ts->gc); 462 if (ret) 463 dev_err(ts->dev, "failed to remove gpio %d\n", 464 ts->gc.base); 465 } 466 } 467 #else 468 static inline int ad7879_gpio_add(struct ad7879 *ts, 469 const struct ad7879_platform_data *pdata) 470 { 471 return 0; 472 } 473 474 static inline void ad7879_gpio_remove(struct ad7879 *ts) 475 { 476 } 477 #endif 478 479 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq, 480 const struct ad7879_bus_ops *bops) 481 { 482 struct ad7879_platform_data *pdata = dev->platform_data; 483 struct ad7879 *ts; 484 struct input_dev *input_dev; 485 int err; 486 u16 revid; 487 488 if (!irq) { 489 dev_err(dev, "no IRQ?\n"); 490 err = -EINVAL; 491 goto err_out; 492 } 493 494 if (!pdata) { 495 dev_err(dev, "no platform data?\n"); 496 err = -EINVAL; 497 goto err_out; 498 } 499 500 ts = kzalloc(sizeof(*ts), GFP_KERNEL); 501 input_dev = input_allocate_device(); 502 if (!ts || !input_dev) { 503 err = -ENOMEM; 504 goto err_free_mem; 505 } 506 507 ts->bops = bops; 508 ts->dev = dev; 509 ts->input = input_dev; 510 ts->irq = irq; 511 512 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); 513 514 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 515 ts->pressure_max = pdata->pressure_max ? : ~0; 516 517 ts->first_conversion_delay = pdata->first_conversion_delay; 518 ts->acquisition_time = pdata->acquisition_time; 519 ts->averaging = pdata->averaging; 520 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 521 ts->median = pdata->median; 522 523 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 524 525 input_dev->name = "AD7879 Touchscreen"; 526 input_dev->phys = ts->phys; 527 input_dev->dev.parent = dev; 528 input_dev->id.bustype = bops->bustype; 529 530 input_dev->open = ad7879_open; 531 input_dev->close = ad7879_close; 532 533 input_set_drvdata(input_dev, ts); 534 535 __set_bit(EV_ABS, input_dev->evbit); 536 __set_bit(ABS_X, input_dev->absbit); 537 __set_bit(ABS_Y, input_dev->absbit); 538 __set_bit(ABS_PRESSURE, input_dev->absbit); 539 540 __set_bit(EV_KEY, input_dev->evbit); 541 __set_bit(BTN_TOUCH, input_dev->keybit); 542 543 input_set_abs_params(input_dev, ABS_X, 544 pdata->x_min ? : 0, 545 pdata->x_max ? : MAX_12BIT, 546 0, 0); 547 input_set_abs_params(input_dev, ABS_Y, 548 pdata->y_min ? : 0, 549 pdata->y_max ? : MAX_12BIT, 550 0, 0); 551 input_set_abs_params(input_dev, ABS_PRESSURE, 552 pdata->pressure_min, pdata->pressure_max, 0, 0); 553 554 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET); 555 if (err < 0) { 556 dev_err(dev, "Failed to write %s\n", input_dev->name); 557 goto err_free_mem; 558 } 559 560 revid = ad7879_read(ts, AD7879_REG_REVID); 561 input_dev->id.product = (revid & 0xff); 562 input_dev->id.version = revid >> 8; 563 if (input_dev->id.product != devid) { 564 dev_err(dev, "Failed to probe %s (%x vs %x)\n", 565 input_dev->name, devid, revid); 566 err = -ENODEV; 567 goto err_free_mem; 568 } 569 570 ts->cmd_crtl3 = AD7879_YPLUS_BIT | 571 AD7879_XPLUS_BIT | 572 AD7879_Z2_BIT | 573 AD7879_Z1_BIT | 574 AD7879_TEMPMASK_BIT | 575 AD7879_AUXVBATMASK_BIT | 576 AD7879_GPIOALERTMASK_BIT; 577 578 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | 579 AD7879_AVG(ts->averaging) | 580 AD7879_MFS(ts->median) | 581 AD7879_FCD(ts->first_conversion_delay); 582 583 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | 584 AD7879_ACQ(ts->acquisition_time) | 585 AD7879_TMR(ts->pen_down_acc_interval); 586 587 err = request_threaded_irq(ts->irq, NULL, ad7879_irq, 588 IRQF_TRIGGER_FALLING, 589 dev_name(dev), ts); 590 if (err) { 591 dev_err(dev, "irq %d busy?\n", ts->irq); 592 goto err_free_mem; 593 } 594 595 __ad7879_disable(ts); 596 597 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group); 598 if (err) 599 goto err_free_irq; 600 601 err = ad7879_gpio_add(ts, pdata); 602 if (err) 603 goto err_remove_attr; 604 605 err = input_register_device(input_dev); 606 if (err) 607 goto err_remove_gpio; 608 609 return ts; 610 611 err_remove_gpio: 612 ad7879_gpio_remove(ts); 613 err_remove_attr: 614 sysfs_remove_group(&dev->kobj, &ad7879_attr_group); 615 err_free_irq: 616 free_irq(ts->irq, ts); 617 err_free_mem: 618 input_free_device(input_dev); 619 kfree(ts); 620 err_out: 621 return ERR_PTR(err); 622 } 623 EXPORT_SYMBOL(ad7879_probe); 624 625 void ad7879_remove(struct ad7879 *ts) 626 { 627 ad7879_gpio_remove(ts); 628 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group); 629 free_irq(ts->irq, ts); 630 input_unregister_device(ts->input); 631 kfree(ts); 632 } 633 EXPORT_SYMBOL(ad7879_remove); 634 635 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 636 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); 637 MODULE_LICENSE("GPL"); 638