1 /* 2 * Copyright (C) 2008 Michael Hennerich, Analog Devices Inc. 3 * 4 * Description: AD7879 based touchscreen, and GPIO driver (I2C/SPI Interface) 5 * 6 * Bugs: Enter bugs at http://blackfin.uclinux.org/ 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, see the file COPYING, or write 20 * to the Free Software Foundation, Inc., 21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 22 * 23 * History: 24 * Copyright (c) 2005 David Brownell 25 * Copyright (c) 2006 Nokia Corporation 26 * Various changes: Imre Deak <imre.deak@nokia.com> 27 * 28 * Using code from: 29 * - corgi_ts.c 30 * Copyright (C) 2004-2005 Richard Purdie 31 * - omap_ts.[hc], ads7846.h, ts_osk.c 32 * Copyright (C) 2002 MontaVista Software 33 * Copyright (C) 2004 Texas Instruments 34 * Copyright (C) 2005 Dirk Behme 35 * - ad7877.c 36 * Copyright (C) 2006-2008 Analog Devices Inc. 37 */ 38 39 #include <linux/device.h> 40 #include <linux/init.h> 41 #include <linux/delay.h> 42 #include <linux/input.h> 43 #include <linux/interrupt.h> 44 #include <linux/irq.h> 45 #include <linux/slab.h> 46 #include <linux/workqueue.h> 47 #include <linux/spi/spi.h> 48 #include <linux/i2c.h> 49 50 #include <linux/spi/ad7879.h> 51 52 #define AD7879_REG_ZEROS 0 53 #define AD7879_REG_CTRL1 1 54 #define AD7879_REG_CTRL2 2 55 #define AD7879_REG_CTRL3 3 56 #define AD7879_REG_AUX1HIGH 4 57 #define AD7879_REG_AUX1LOW 5 58 #define AD7879_REG_TEMP1HIGH 6 59 #define AD7879_REG_TEMP1LOW 7 60 #define AD7879_REG_XPLUS 8 61 #define AD7879_REG_YPLUS 9 62 #define AD7879_REG_Z1 10 63 #define AD7879_REG_Z2 11 64 #define AD7879_REG_AUXVBAT 12 65 #define AD7879_REG_TEMP 13 66 #define AD7879_REG_REVID 14 67 68 /* Control REG 1 */ 69 #define AD7879_TMR(x) ((x & 0xFF) << 0) 70 #define AD7879_ACQ(x) ((x & 0x3) << 8) 71 #define AD7879_MODE_NOC (0 << 10) /* Do not convert */ 72 #define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */ 73 #define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */ 74 #define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */ 75 #define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */ 76 77 /* Control REG 2 */ 78 #define AD7879_FCD(x) ((x & 0x3) << 0) 79 #define AD7879_RESET (1 << 4) 80 #define AD7879_MFS(x) ((x & 0x3) << 5) 81 #define AD7879_AVG(x) ((x & 0x3) << 7) 82 #define AD7879_SER (1 << 9) /* non-differential */ 83 #define AD7879_DFR (0 << 9) /* differential */ 84 #define AD7879_GPIOPOL (1 << 10) 85 #define AD7879_GPIODIR (1 << 11) 86 #define AD7879_GPIO_DATA (1 << 12) 87 #define AD7879_GPIO_EN (1 << 13) 88 #define AD7879_PM(x) ((x & 0x3) << 14) 89 #define AD7879_PM_SHUTDOWN (0) 90 #define AD7879_PM_DYN (1) 91 #define AD7879_PM_FULLON (2) 92 93 /* Control REG 3 */ 94 #define AD7879_TEMPMASK_BIT (1<<15) 95 #define AD7879_AUXVBATMASK_BIT (1<<14) 96 #define AD7879_INTMODE_BIT (1<<13) 97 #define AD7879_GPIOALERTMASK_BIT (1<<12) 98 #define AD7879_AUXLOW_BIT (1<<11) 99 #define AD7879_AUXHIGH_BIT (1<<10) 100 #define AD7879_TEMPLOW_BIT (1<<9) 101 #define AD7879_TEMPHIGH_BIT (1<<8) 102 #define AD7879_YPLUS_BIT (1<<7) 103 #define AD7879_XPLUS_BIT (1<<6) 104 #define AD7879_Z1_BIT (1<<5) 105 #define AD7879_Z2_BIT (1<<4) 106 #define AD7879_AUX_BIT (1<<3) 107 #define AD7879_VBAT_BIT (1<<2) 108 #define AD7879_TEMP_BIT (1<<1) 109 110 enum { 111 AD7879_SEQ_XPOS = 0, 112 AD7879_SEQ_YPOS = 1, 113 AD7879_SEQ_Z1 = 2, 114 AD7879_SEQ_Z2 = 3, 115 AD7879_NR_SENSE = 4, 116 }; 117 118 #define MAX_12BIT ((1<<12)-1) 119 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50) 120 121 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE) 122 #define AD7879_DEVID 0x7A 123 typedef struct spi_device bus_device; 124 #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE) 125 #define AD7879_DEVID 0x79 126 typedef struct i2c_client bus_device; 127 #endif 128 129 struct ad7879 { 130 bus_device *bus; 131 struct input_dev *input; 132 struct work_struct work; 133 struct timer_list timer; 134 135 struct mutex mutex; 136 unsigned disabled:1; /* P: mutex */ 137 138 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE) 139 struct spi_message msg; 140 struct spi_transfer xfer[AD7879_NR_SENSE + 1]; 141 u16 cmd; 142 #endif 143 u16 conversion_data[AD7879_NR_SENSE]; 144 char phys[32]; 145 u8 first_conversion_delay; 146 u8 acquisition_time; 147 u8 averaging; 148 u8 pen_down_acc_interval; 149 u8 median; 150 u16 x_plate_ohms; 151 u16 pressure_max; 152 u16 gpio_init; 153 u16 cmd_crtl1; 154 u16 cmd_crtl2; 155 u16 cmd_crtl3; 156 unsigned gpio:1; 157 }; 158 159 static int ad7879_read(bus_device *, u8); 160 static int ad7879_write(bus_device *, u8, u16); 161 static void ad7879_collect(struct ad7879 *); 162 163 static void ad7879_report(struct ad7879 *ts) 164 { 165 struct input_dev *input_dev = ts->input; 166 unsigned Rt; 167 u16 x, y, z1, z2; 168 169 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT; 170 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT; 171 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT; 172 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT; 173 174 /* 175 * The samples processed here are already preprocessed by the AD7879. 176 * The preprocessing function consists of a median and an averaging filter. 177 * The combination of these two techniques provides a robust solution, 178 * discarding the spurious noise in the signal and keeping only the data of interest. 179 * The size of both filters is programmable. (dev.platform_data, see linux/spi/ad7879.h) 180 * Other user-programmable conversion controls include variable acquisition time, 181 * and first conversion delay. Up to 16 averages can be taken per conversion. 182 */ 183 184 if (likely(x && z1)) { 185 /* compute touch pressure resistance using equation #1 */ 186 Rt = (z2 - z1) * x * ts->x_plate_ohms; 187 Rt /= z1; 188 Rt = (Rt + 2047) >> 12; 189 190 input_report_abs(input_dev, ABS_X, x); 191 input_report_abs(input_dev, ABS_Y, y); 192 input_report_abs(input_dev, ABS_PRESSURE, Rt); 193 input_sync(input_dev); 194 } 195 } 196 197 static void ad7879_work(struct work_struct *work) 198 { 199 struct ad7879 *ts = container_of(work, struct ad7879, work); 200 201 /* use keventd context to read the result registers */ 202 ad7879_collect(ts); 203 ad7879_report(ts); 204 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 205 } 206 207 static void ad7879_ts_event_release(struct ad7879 *ts) 208 { 209 struct input_dev *input_dev = ts->input; 210 211 input_report_abs(input_dev, ABS_PRESSURE, 0); 212 input_sync(input_dev); 213 } 214 215 static void ad7879_timer(unsigned long handle) 216 { 217 struct ad7879 *ts = (void *)handle; 218 219 ad7879_ts_event_release(ts); 220 } 221 222 static irqreturn_t ad7879_irq(int irq, void *handle) 223 { 224 struct ad7879 *ts = handle; 225 226 /* The repeated conversion sequencer controlled by TMR kicked off too fast. 227 * We ignore the last and process the sample sequence currently in the queue. 228 * It can't be older than 9.4ms 229 */ 230 231 if (!work_pending(&ts->work)) 232 schedule_work(&ts->work); 233 234 return IRQ_HANDLED; 235 } 236 237 static void ad7879_setup(struct ad7879 *ts) 238 { 239 ts->cmd_crtl3 = AD7879_YPLUS_BIT | 240 AD7879_XPLUS_BIT | 241 AD7879_Z2_BIT | 242 AD7879_Z1_BIT | 243 AD7879_TEMPMASK_BIT | 244 AD7879_AUXVBATMASK_BIT | 245 AD7879_GPIOALERTMASK_BIT; 246 247 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR | 248 AD7879_AVG(ts->averaging) | 249 AD7879_MFS(ts->median) | 250 AD7879_FCD(ts->first_conversion_delay) | 251 ts->gpio_init; 252 253 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 | 254 AD7879_ACQ(ts->acquisition_time) | 255 AD7879_TMR(ts->pen_down_acc_interval); 256 257 ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2); 258 ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3); 259 ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1); 260 } 261 262 static void ad7879_disable(struct ad7879 *ts) 263 { 264 mutex_lock(&ts->mutex); 265 266 if (!ts->disabled) { 267 268 ts->disabled = 1; 269 disable_irq(ts->bus->irq); 270 271 cancel_work_sync(&ts->work); 272 273 if (del_timer_sync(&ts->timer)) 274 ad7879_ts_event_release(ts); 275 276 ad7879_write(ts->bus, AD7879_REG_CTRL2, 277 AD7879_PM(AD7879_PM_SHUTDOWN)); 278 } 279 280 mutex_unlock(&ts->mutex); 281 } 282 283 static void ad7879_enable(struct ad7879 *ts) 284 { 285 mutex_lock(&ts->mutex); 286 287 if (ts->disabled) { 288 ad7879_setup(ts); 289 ts->disabled = 0; 290 enable_irq(ts->bus->irq); 291 } 292 293 mutex_unlock(&ts->mutex); 294 } 295 296 static ssize_t ad7879_disable_show(struct device *dev, 297 struct device_attribute *attr, char *buf) 298 { 299 struct ad7879 *ts = dev_get_drvdata(dev); 300 301 return sprintf(buf, "%u\n", ts->disabled); 302 } 303 304 static ssize_t ad7879_disable_store(struct device *dev, 305 struct device_attribute *attr, 306 const char *buf, size_t count) 307 { 308 struct ad7879 *ts = dev_get_drvdata(dev); 309 unsigned long val; 310 int error; 311 312 error = strict_strtoul(buf, 10, &val); 313 if (error) 314 return error; 315 316 if (val) 317 ad7879_disable(ts); 318 else 319 ad7879_enable(ts); 320 321 return count; 322 } 323 324 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store); 325 326 static ssize_t ad7879_gpio_show(struct device *dev, 327 struct device_attribute *attr, char *buf) 328 { 329 struct ad7879 *ts = dev_get_drvdata(dev); 330 331 return sprintf(buf, "%u\n", ts->gpio); 332 } 333 334 static ssize_t ad7879_gpio_store(struct device *dev, 335 struct device_attribute *attr, 336 const char *buf, size_t count) 337 { 338 struct ad7879 *ts = dev_get_drvdata(dev); 339 unsigned long val; 340 int error; 341 342 error = strict_strtoul(buf, 10, &val); 343 if (error) 344 return error; 345 346 mutex_lock(&ts->mutex); 347 ts->gpio = !!val; 348 error = ad7879_write(ts->bus, AD7879_REG_CTRL2, 349 ts->gpio ? 350 ts->cmd_crtl2 & ~AD7879_GPIO_DATA : 351 ts->cmd_crtl2 | AD7879_GPIO_DATA); 352 mutex_unlock(&ts->mutex); 353 354 return error ? : count; 355 } 356 357 static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store); 358 359 static struct attribute *ad7879_attributes[] = { 360 &dev_attr_disable.attr, 361 &dev_attr_gpio.attr, 362 NULL 363 }; 364 365 static const struct attribute_group ad7879_attr_group = { 366 .attrs = ad7879_attributes, 367 }; 368 369 static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts) 370 { 371 struct input_dev *input_dev; 372 struct ad7879_platform_data *pdata = bus->dev.platform_data; 373 int err; 374 u16 revid; 375 376 if (!bus->irq) { 377 dev_err(&bus->dev, "no IRQ?\n"); 378 return -ENODEV; 379 } 380 381 if (!pdata) { 382 dev_err(&bus->dev, "no platform data?\n"); 383 return -ENODEV; 384 } 385 386 input_dev = input_allocate_device(); 387 if (!input_dev) 388 return -ENOMEM; 389 390 ts->input = input_dev; 391 392 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts); 393 INIT_WORK(&ts->work, ad7879_work); 394 mutex_init(&ts->mutex); 395 396 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 397 ts->pressure_max = pdata->pressure_max ? : ~0; 398 399 ts->first_conversion_delay = pdata->first_conversion_delay; 400 ts->acquisition_time = pdata->acquisition_time; 401 ts->averaging = pdata->averaging; 402 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 403 ts->median = pdata->median; 404 405 if (pdata->gpio_output) 406 ts->gpio_init = AD7879_GPIO_EN | 407 (pdata->gpio_default ? 0 : AD7879_GPIO_DATA); 408 else 409 ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR; 410 411 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev)); 412 413 input_dev->name = "AD7879 Touchscreen"; 414 input_dev->phys = ts->phys; 415 input_dev->dev.parent = &bus->dev; 416 417 __set_bit(EV_ABS, input_dev->evbit); 418 __set_bit(ABS_X, input_dev->absbit); 419 __set_bit(ABS_Y, input_dev->absbit); 420 __set_bit(ABS_PRESSURE, input_dev->absbit); 421 422 input_set_abs_params(input_dev, ABS_X, 423 pdata->x_min ? : 0, 424 pdata->x_max ? : MAX_12BIT, 425 0, 0); 426 input_set_abs_params(input_dev, ABS_Y, 427 pdata->y_min ? : 0, 428 pdata->y_max ? : MAX_12BIT, 429 0, 0); 430 input_set_abs_params(input_dev, ABS_PRESSURE, 431 pdata->pressure_min, pdata->pressure_max, 0, 0); 432 433 err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET); 434 435 if (err < 0) { 436 dev_err(&bus->dev, "Failed to write %s\n", input_dev->name); 437 goto err_free_mem; 438 } 439 440 revid = ad7879_read(bus, AD7879_REG_REVID); 441 442 if ((revid & 0xFF) != AD7879_DEVID) { 443 dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name); 444 err = -ENODEV; 445 goto err_free_mem; 446 } 447 448 ad7879_setup(ts); 449 450 err = request_irq(bus->irq, ad7879_irq, 451 IRQF_TRIGGER_FALLING | IRQF_SAMPLE_RANDOM, 452 bus->dev.driver->name, ts); 453 454 if (err) { 455 dev_err(&bus->dev, "irq %d busy?\n", bus->irq); 456 goto err_free_mem; 457 } 458 459 err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group); 460 if (err) 461 goto err_free_irq; 462 463 err = input_register_device(input_dev); 464 if (err) 465 goto err_remove_attr; 466 467 dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n", 468 revid >> 8, bus->irq); 469 470 return 0; 471 472 err_remove_attr: 473 sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group); 474 err_free_irq: 475 free_irq(bus->irq, ts); 476 err_free_mem: 477 input_free_device(input_dev); 478 479 return err; 480 } 481 482 static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts) 483 { 484 ad7879_disable(ts); 485 sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group); 486 free_irq(ts->bus->irq, ts); 487 input_unregister_device(ts->input); 488 dev_dbg(&bus->dev, "unregistered touchscreen\n"); 489 490 return 0; 491 } 492 493 #ifdef CONFIG_PM 494 static int ad7879_suspend(bus_device *bus, pm_message_t message) 495 { 496 struct ad7879 *ts = dev_get_drvdata(&bus->dev); 497 498 ad7879_disable(ts); 499 500 return 0; 501 } 502 503 static int ad7879_resume(bus_device *bus) 504 { 505 struct ad7879 *ts = dev_get_drvdata(&bus->dev); 506 507 ad7879_enable(ts); 508 509 return 0; 510 } 511 #else 512 #define ad7879_suspend NULL 513 #define ad7879_resume NULL 514 #endif 515 516 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE) 517 #define MAX_SPI_FREQ_HZ 5000000 518 #define AD7879_CMD_MAGIC 0xE000 519 #define AD7879_CMD_READ (1 << 10) 520 #define AD7879_WRITECMD(reg) (AD7879_CMD_MAGIC | (reg & 0xF)) 521 #define AD7879_READCMD(reg) (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF)) 522 523 struct ser_req { 524 u16 command; 525 u16 data; 526 struct spi_message msg; 527 struct spi_transfer xfer[2]; 528 }; 529 530 /* 531 * ad7879_read/write are only used for initial setup and for sysfs controls. 532 * The main traffic is done in ad7879_collect(). 533 */ 534 535 static int ad7879_read(struct spi_device *spi, u8 reg) 536 { 537 struct ser_req *req; 538 int status, ret; 539 540 req = kzalloc(sizeof *req, GFP_KERNEL); 541 if (!req) 542 return -ENOMEM; 543 544 spi_message_init(&req->msg); 545 546 req->command = (u16) AD7879_READCMD(reg); 547 req->xfer[0].tx_buf = &req->command; 548 req->xfer[0].len = 2; 549 550 req->xfer[1].rx_buf = &req->data; 551 req->xfer[1].len = 2; 552 553 spi_message_add_tail(&req->xfer[0], &req->msg); 554 spi_message_add_tail(&req->xfer[1], &req->msg); 555 556 status = spi_sync(spi, &req->msg); 557 ret = status ? : req->data; 558 559 kfree(req); 560 561 return ret; 562 } 563 564 static int ad7879_write(struct spi_device *spi, u8 reg, u16 val) 565 { 566 struct ser_req *req; 567 int status; 568 569 req = kzalloc(sizeof *req, GFP_KERNEL); 570 if (!req) 571 return -ENOMEM; 572 573 spi_message_init(&req->msg); 574 575 req->command = (u16) AD7879_WRITECMD(reg); 576 req->xfer[0].tx_buf = &req->command; 577 req->xfer[0].len = 2; 578 579 req->data = val; 580 req->xfer[1].tx_buf = &req->data; 581 req->xfer[1].len = 2; 582 583 spi_message_add_tail(&req->xfer[0], &req->msg); 584 spi_message_add_tail(&req->xfer[1], &req->msg); 585 586 status = spi_sync(spi, &req->msg); 587 588 kfree(req); 589 590 return status; 591 } 592 593 static void ad7879_collect(struct ad7879 *ts) 594 { 595 int status = spi_sync(ts->bus, &ts->msg); 596 597 if (status) 598 dev_err(&ts->bus->dev, "spi_sync --> %d\n", status); 599 } 600 601 static void ad7879_setup_ts_def_msg(struct ad7879 *ts) 602 { 603 struct spi_message *m; 604 int i; 605 606 ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS); 607 608 m = &ts->msg; 609 spi_message_init(m); 610 ts->xfer[0].tx_buf = &ts->cmd; 611 ts->xfer[0].len = 2; 612 613 spi_message_add_tail(&ts->xfer[0], m); 614 615 for (i = 0; i < AD7879_NR_SENSE; i++) { 616 ts->xfer[i + 1].rx_buf = &ts->conversion_data[i]; 617 ts->xfer[i + 1].len = 2; 618 spi_message_add_tail(&ts->xfer[i + 1], m); 619 } 620 } 621 622 static int __devinit ad7879_probe(struct spi_device *spi) 623 { 624 struct ad7879 *ts; 625 int error; 626 627 /* don't exceed max specified SPI CLK frequency */ 628 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 629 dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz); 630 return -EINVAL; 631 } 632 633 ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL); 634 if (!ts) 635 return -ENOMEM; 636 637 dev_set_drvdata(&spi->dev, ts); 638 ts->bus = spi; 639 640 ad7879_setup_ts_def_msg(ts); 641 642 error = ad7879_construct(spi, ts); 643 if (error) { 644 dev_set_drvdata(&spi->dev, NULL); 645 kfree(ts); 646 } 647 648 return 0; 649 } 650 651 static int __devexit ad7879_remove(struct spi_device *spi) 652 { 653 struct ad7879 *ts = dev_get_drvdata(&spi->dev); 654 655 ad7879_destroy(spi, ts); 656 dev_set_drvdata(&spi->dev, NULL); 657 kfree(ts); 658 659 return 0; 660 } 661 662 static struct spi_driver ad7879_driver = { 663 .driver = { 664 .name = "ad7879", 665 .bus = &spi_bus_type, 666 .owner = THIS_MODULE, 667 }, 668 .probe = ad7879_probe, 669 .remove = __devexit_p(ad7879_remove), 670 .suspend = ad7879_suspend, 671 .resume = ad7879_resume, 672 }; 673 674 static int __init ad7879_init(void) 675 { 676 return spi_register_driver(&ad7879_driver); 677 } 678 module_init(ad7879_init); 679 680 static void __exit ad7879_exit(void) 681 { 682 spi_unregister_driver(&ad7879_driver); 683 } 684 module_exit(ad7879_exit); 685 686 #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE) 687 688 /* All registers are word-sized. 689 * AD7879 uses a high-byte first convention. 690 */ 691 static int ad7879_read(struct i2c_client *client, u8 reg) 692 { 693 return swab16(i2c_smbus_read_word_data(client, reg)); 694 } 695 696 static int ad7879_write(struct i2c_client *client, u8 reg, u16 val) 697 { 698 return i2c_smbus_write_word_data(client, reg, swab16(val)); 699 } 700 701 static void ad7879_collect(struct ad7879 *ts) 702 { 703 int i; 704 705 for (i = 0; i < AD7879_NR_SENSE; i++) 706 ts->conversion_data[i] = ad7879_read(ts->bus, 707 AD7879_REG_XPLUS + i); 708 } 709 710 static int __devinit ad7879_probe(struct i2c_client *client, 711 const struct i2c_device_id *id) 712 { 713 struct ad7879 *ts; 714 int error; 715 716 if (!i2c_check_functionality(client->adapter, 717 I2C_FUNC_SMBUS_WORD_DATA)) { 718 dev_err(&client->dev, "SMBUS Word Data not Supported\n"); 719 return -EIO; 720 } 721 722 ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL); 723 if (!ts) 724 return -ENOMEM; 725 726 i2c_set_clientdata(client, ts); 727 ts->bus = client; 728 729 error = ad7879_construct(client, ts); 730 if (error) { 731 i2c_set_clientdata(client, NULL); 732 kfree(ts); 733 } 734 735 return 0; 736 } 737 738 static int __devexit ad7879_remove(struct i2c_client *client) 739 { 740 struct ad7879 *ts = dev_get_drvdata(&client->dev); 741 742 ad7879_destroy(client, ts); 743 i2c_set_clientdata(client, NULL); 744 kfree(ts); 745 746 return 0; 747 } 748 749 static const struct i2c_device_id ad7879_id[] = { 750 { "ad7879", 0 }, 751 { } 752 }; 753 MODULE_DEVICE_TABLE(i2c, ad7879_id); 754 755 static struct i2c_driver ad7879_driver = { 756 .driver = { 757 .name = "ad7879", 758 .owner = THIS_MODULE, 759 }, 760 .probe = ad7879_probe, 761 .remove = __devexit_p(ad7879_remove), 762 .suspend = ad7879_suspend, 763 .resume = ad7879_resume, 764 .id_table = ad7879_id, 765 }; 766 767 static int __init ad7879_init(void) 768 { 769 return i2c_add_driver(&ad7879_driver); 770 } 771 module_init(ad7879_init); 772 773 static void __exit ad7879_exit(void) 774 { 775 i2c_del_driver(&ad7879_driver); 776 } 777 module_exit(ad7879_exit); 778 #endif 779 780 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 781 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver"); 782 MODULE_LICENSE("GPL"); 783