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