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 void ad7879_suspend(struct ad7879 *ts) 285 { 286 mutex_lock(&ts->input->mutex); 287 288 if (!ts->suspended && !ts->disabled && ts->input->users) 289 __ad7879_disable(ts); 290 291 ts->suspended = true; 292 293 mutex_unlock(&ts->input->mutex); 294 } 295 EXPORT_SYMBOL(ad7879_suspend); 296 297 void ad7879_resume(struct ad7879 *ts) 298 { 299 mutex_lock(&ts->input->mutex); 300 301 if (ts->suspended && !ts->disabled && ts->input->users) 302 __ad7879_enable(ts); 303 304 ts->suspended = false; 305 306 mutex_unlock(&ts->input->mutex); 307 } 308 EXPORT_SYMBOL(ad7879_resume); 309 310 static void ad7879_toggle(struct ad7879 *ts, bool disable) 311 { 312 mutex_lock(&ts->input->mutex); 313 314 if (!ts->suspended && ts->input->users != 0) { 315 316 if (disable) { 317 if (ts->disabled) 318 __ad7879_enable(ts); 319 } else { 320 if (!ts->disabled) 321 __ad7879_disable(ts); 322 } 323 } 324 325 ts->disabled = disable; 326 327 mutex_unlock(&ts->input->mutex); 328 } 329 330 static ssize_t ad7879_disable_show(struct device *dev, 331 struct device_attribute *attr, char *buf) 332 { 333 struct ad7879 *ts = dev_get_drvdata(dev); 334 335 return sprintf(buf, "%u\n", ts->disabled); 336 } 337 338 static ssize_t ad7879_disable_store(struct device *dev, 339 struct device_attribute *attr, 340 const char *buf, size_t count) 341 { 342 struct ad7879 *ts = dev_get_drvdata(dev); 343 unsigned long val; 344 int error; 345 346 error = strict_strtoul(buf, 10, &val); 347 if (error) 348 return error; 349 350 ad7879_toggle(ts, val); 351 352 return count; 353 } 354 355 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); 356 357 static struct attribute *ad7879_attributes[] = { 358 &dev_attr_disable.attr, 359 NULL 360 }; 361 362 static const struct attribute_group ad7879_attr_group = { 363 .attrs = ad7879_attributes, 364 }; 365 366 #ifdef CONFIG_GPIOLIB 367 static int ad7879_gpio_direction_input(struct gpio_chip *chip, 368 unsigned gpio) 369 { 370 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 371 int err; 372 373 mutex_lock(&ts->mutex); 374 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL; 375 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 376 mutex_unlock(&ts->mutex); 377 378 return err; 379 } 380 381 static int ad7879_gpio_direction_output(struct gpio_chip *chip, 382 unsigned gpio, int level) 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_GPIODIR; 389 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL; 390 if (level) 391 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 392 else 393 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 394 395 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 396 mutex_unlock(&ts->mutex); 397 398 return err; 399 } 400 401 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio) 402 { 403 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 404 u16 val; 405 406 mutex_lock(&ts->mutex); 407 val = ad7879_read(ts, AD7879_REG_CTRL2); 408 mutex_unlock(&ts->mutex); 409 410 return !!(val & AD7879_GPIO_DATA); 411 } 412 413 static void ad7879_gpio_set_value(struct gpio_chip *chip, 414 unsigned gpio, int value) 415 { 416 struct ad7879 *ts = container_of(chip, struct ad7879, gc); 417 418 mutex_lock(&ts->mutex); 419 if (value) 420 ts->cmd_crtl2 |= AD7879_GPIO_DATA; 421 else 422 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA; 423 424 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2); 425 mutex_unlock(&ts->mutex); 426 } 427 428 static int ad7879_gpio_add(struct ad7879 *ts, 429 const struct ad7879_platform_data *pdata) 430 { 431 int ret = 0; 432 433 mutex_init(&ts->mutex); 434 435 if (pdata->gpio_export) { 436 ts->gc.direction_input = ad7879_gpio_direction_input; 437 ts->gc.direction_output = ad7879_gpio_direction_output; 438 ts->gc.get = ad7879_gpio_get_value; 439 ts->gc.set = ad7879_gpio_set_value; 440 ts->gc.can_sleep = 1; 441 ts->gc.base = pdata->gpio_base; 442 ts->gc.ngpio = 1; 443 ts->gc.label = "AD7879-GPIO"; 444 ts->gc.owner = THIS_MODULE; 445 ts->gc.dev = ts->dev; 446 447 ret = gpiochip_add(&ts->gc); 448 if (ret) 449 dev_err(ts->dev, "failed to register gpio %d\n", 450 ts->gc.base); 451 } 452 453 return ret; 454 } 455 456 static void ad7879_gpio_remove(struct ad7879 *ts) 457 { 458 const struct ad7879_platform_data *pdata = ts->dev->platform_data; 459 int ret; 460 461 if (pdata->gpio_export) { 462 ret = gpiochip_remove(&ts->gc); 463 if (ret) 464 dev_err(ts->dev, "failed to remove gpio %d\n", 465 ts->gc.base); 466 } 467 } 468 #else 469 static inline int ad7879_gpio_add(struct ad7879 *ts, 470 const struct ad7879_platform_data *pdata) 471 { 472 return 0; 473 } 474 475 static inline void ad7879_gpio_remove(struct ad7879 *ts) 476 { 477 } 478 #endif 479 480 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq, 481 const struct ad7879_bus_ops *bops) 482 { 483 struct ad7879_platform_data *pdata = dev->platform_data; 484 struct ad7879 *ts; 485 struct input_dev *input_dev; 486 int err; 487 u16 revid; 488 489 if (!irq) { 490 dev_err(dev, "no IRQ?\n"); 491 err = -EINVAL; 492 goto err_out; 493 } 494 495 if (!pdata) { 496 dev_err(dev, "no platform data?\n"); 497 err = -EINVAL; 498 goto err_out; 499 } 500 501 ts = kzalloc(sizeof(*ts), GFP_KERNEL); 502 input_dev = input_allocate_device(); 503 if (!ts || !input_dev) { 504 err = -ENOMEM; 505 goto err_free_mem; 506 } 507 508 ts->bops = bops; 509 ts->dev = dev; 510 ts->input = input_dev; 511 ts->irq = irq; 512 513 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); 514 515 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 516 ts->pressure_max = pdata->pressure_max ? : ~0; 517 518 ts->first_conversion_delay = pdata->first_conversion_delay; 519 ts->acquisition_time = pdata->acquisition_time; 520 ts->averaging = pdata->averaging; 521 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 522 ts->median = pdata->median; 523 524 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); 525 526 input_dev->name = "AD7879 Touchscreen"; 527 input_dev->phys = ts->phys; 528 input_dev->dev.parent = dev; 529 input_dev->id.bustype = bops->bustype; 530 531 input_dev->open = ad7879_open; 532 input_dev->close = ad7879_close; 533 534 input_set_drvdata(input_dev, ts); 535 536 __set_bit(EV_ABS, input_dev->evbit); 537 __set_bit(ABS_X, input_dev->absbit); 538 __set_bit(ABS_Y, input_dev->absbit); 539 __set_bit(ABS_PRESSURE, input_dev->absbit); 540 541 __set_bit(EV_KEY, input_dev->evbit); 542 __set_bit(BTN_TOUCH, input_dev->keybit); 543 544 input_set_abs_params(input_dev, ABS_X, 545 pdata->x_min ? : 0, 546 pdata->x_max ? : MAX_12BIT, 547 0, 0); 548 input_set_abs_params(input_dev, ABS_Y, 549 pdata->y_min ? : 0, 550 pdata->y_max ? : MAX_12BIT, 551 0, 0); 552 input_set_abs_params(input_dev, ABS_PRESSURE, 553 pdata->pressure_min, pdata->pressure_max, 0, 0); 554 555 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET); 556 if (err < 0) { 557 dev_err(dev, "Failed to write %s\n", input_dev->name); 558 goto err_free_mem; 559 } 560 561 revid = ad7879_read(ts, AD7879_REG_REVID); 562 input_dev->id.product = (revid & 0xff); 563 input_dev->id.version = revid >> 8; 564 if (input_dev->id.product != devid) { 565 dev_err(dev, "Failed to probe %s (%x vs %x)\n", 566 input_dev->name, devid, revid); 567 err = -ENODEV; 568 goto err_free_mem; 569 } 570 571 ts->cmd_crtl3 = AD7879_YPLUS_BIT | 572 AD7879_XPLUS_BIT | 573 AD7879_Z2_BIT | 574 AD7879_Z1_BIT | 575 AD7879_TEMPMASK_BIT | 576 AD7879_AUXVBATMASK_BIT | 577 AD7879_GPIOALERTMASK_BIT; 578 579 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | 580 AD7879_AVG(ts->averaging) | 581 AD7879_MFS(ts->median) | 582 AD7879_FCD(ts->first_conversion_delay); 583 584 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | 585 AD7879_ACQ(ts->acquisition_time) | 586 AD7879_TMR(ts->pen_down_acc_interval); 587 588 err = request_threaded_irq(ts->irq, NULL, ad7879_irq, 589 IRQF_TRIGGER_FALLING, 590 dev_name(dev), ts); 591 if (err) { 592 dev_err(dev, "irq %d busy?\n", ts->irq); 593 goto err_free_mem; 594 } 595 596 __ad7879_disable(ts); 597 598 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group); 599 if (err) 600 goto err_free_irq; 601 602 err = ad7879_gpio_add(ts, pdata); 603 if (err) 604 goto err_remove_attr; 605 606 err = input_register_device(input_dev); 607 if (err) 608 goto err_remove_gpio; 609 610 return ts; 611 612 err_remove_gpio: 613 ad7879_gpio_remove(ts); 614 err_remove_attr: 615 sysfs_remove_group(&dev->kobj, &ad7879_attr_group); 616 err_free_irq: 617 free_irq(ts->irq, ts); 618 err_free_mem: 619 input_free_device(input_dev); 620 kfree(ts); 621 err_out: 622 return ERR_PTR(err); 623 } 624 EXPORT_SYMBOL(ad7879_probe); 625 626 void ad7879_remove(struct ad7879 *ts) 627 { 628 ad7879_gpio_remove(ts); 629 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group); 630 free_irq(ts->irq, ts); 631 input_unregister_device(ts->input); 632 kfree(ts); 633 } 634 EXPORT_SYMBOL(ad7879_remove); 635 636 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 637 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); 638 MODULE_LICENSE("GPL"); 639