1 /* 2 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc. 3 * 4 * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver 5 * Based on: ads7846.c 6 * 7 * Bugs: Enter bugs at http://blackfin.uclinux.org/ 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, see the file COPYING, or write 21 * to the Free Software Foundation, Inc., 22 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 23 * 24 * History: 25 * Copyright (c) 2005 David Brownell 26 * Copyright (c) 2006 Nokia Corporation 27 * Various changes: Imre Deak <imre.deak@nokia.com> 28 * 29 * Using code from: 30 * - corgi_ts.c 31 * Copyright (C) 2004-2005 Richard Purdie 32 * - omap_ts.[hc], ads7846.h, ts_osk.c 33 * Copyright (C) 2002 MontaVista Software 34 * Copyright (C) 2004 Texas Instruments 35 * Copyright (C) 2005 Dirk Behme 36 */ 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/slab.h> 45 #include <linux/spi/spi.h> 46 #include <linux/spi/ad7877.h> 47 #include <asm/irq.h> 48 49 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100) 50 51 #define MAX_SPI_FREQ_HZ 20000000 52 #define MAX_12BIT ((1<<12)-1) 53 54 #define AD7877_REG_ZEROS 0 55 #define AD7877_REG_CTRL1 1 56 #define AD7877_REG_CTRL2 2 57 #define AD7877_REG_ALERT 3 58 #define AD7877_REG_AUX1HIGH 4 59 #define AD7877_REG_AUX1LOW 5 60 #define AD7877_REG_BAT1HIGH 6 61 #define AD7877_REG_BAT1LOW 7 62 #define AD7877_REG_BAT2HIGH 8 63 #define AD7877_REG_BAT2LOW 9 64 #define AD7877_REG_TEMP1HIGH 10 65 #define AD7877_REG_TEMP1LOW 11 66 #define AD7877_REG_SEQ0 12 67 #define AD7877_REG_SEQ1 13 68 #define AD7877_REG_DAC 14 69 #define AD7877_REG_NONE1 15 70 #define AD7877_REG_EXTWRITE 15 71 #define AD7877_REG_XPLUS 16 72 #define AD7877_REG_YPLUS 17 73 #define AD7877_REG_Z2 18 74 #define AD7877_REG_aux1 19 75 #define AD7877_REG_aux2 20 76 #define AD7877_REG_aux3 21 77 #define AD7877_REG_bat1 22 78 #define AD7877_REG_bat2 23 79 #define AD7877_REG_temp1 24 80 #define AD7877_REG_temp2 25 81 #define AD7877_REG_Z1 26 82 #define AD7877_REG_GPIOCTRL1 27 83 #define AD7877_REG_GPIOCTRL2 28 84 #define AD7877_REG_GPIODATA 29 85 #define AD7877_REG_NONE2 30 86 #define AD7877_REG_NONE3 31 87 88 #define AD7877_SEQ_YPLUS_BIT (1<<11) 89 #define AD7877_SEQ_XPLUS_BIT (1<<10) 90 #define AD7877_SEQ_Z2_BIT (1<<9) 91 #define AD7877_SEQ_AUX1_BIT (1<<8) 92 #define AD7877_SEQ_AUX2_BIT (1<<7) 93 #define AD7877_SEQ_AUX3_BIT (1<<6) 94 #define AD7877_SEQ_BAT1_BIT (1<<5) 95 #define AD7877_SEQ_BAT2_BIT (1<<4) 96 #define AD7877_SEQ_TEMP1_BIT (1<<3) 97 #define AD7877_SEQ_TEMP2_BIT (1<<2) 98 #define AD7877_SEQ_Z1_BIT (1<<1) 99 100 enum { 101 AD7877_SEQ_YPOS = 0, 102 AD7877_SEQ_XPOS = 1, 103 AD7877_SEQ_Z2 = 2, 104 AD7877_SEQ_AUX1 = 3, 105 AD7877_SEQ_AUX2 = 4, 106 AD7877_SEQ_AUX3 = 5, 107 AD7877_SEQ_BAT1 = 6, 108 AD7877_SEQ_BAT2 = 7, 109 AD7877_SEQ_TEMP1 = 8, 110 AD7877_SEQ_TEMP2 = 9, 111 AD7877_SEQ_Z1 = 10, 112 AD7877_NR_SENSE = 11, 113 }; 114 115 /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */ 116 #define AD7877_DAC_CONF 0x1 117 118 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */ 119 #define AD7877_EXTW_GPIO_3_CONF 0x1C4 120 #define AD7877_EXTW_GPIO_DATA 0x200 121 122 /* Control REG 2 */ 123 #define AD7877_TMR(x) ((x & 0x3) << 0) 124 #define AD7877_REF(x) ((x & 0x1) << 2) 125 #define AD7877_POL(x) ((x & 0x1) << 3) 126 #define AD7877_FCD(x) ((x & 0x3) << 4) 127 #define AD7877_PM(x) ((x & 0x3) << 6) 128 #define AD7877_ACQ(x) ((x & 0x3) << 8) 129 #define AD7877_AVG(x) ((x & 0x3) << 10) 130 131 /* Control REG 1 */ 132 #define AD7877_SER (1 << 11) /* non-differential */ 133 #define AD7877_DFR (0 << 11) /* differential */ 134 135 #define AD7877_MODE_NOC (0) /* Do not convert */ 136 #define AD7877_MODE_SCC (1) /* Single channel conversion */ 137 #define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */ 138 #define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */ 139 140 #define AD7877_CHANADD(x) ((x&0xF)<<7) 141 #define AD7877_READADD(x) ((x)<<2) 142 #define AD7877_WRITEADD(x) ((x)<<12) 143 144 #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \ 145 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \ 146 AD7877_READADD(AD7877_REG_ ## x)) 147 148 #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \ 149 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT) 150 151 /* 152 * Non-touchscreen sensors only use single-ended conversions. 153 */ 154 155 struct ser_req { 156 u16 reset; 157 u16 ref_on; 158 u16 command; 159 struct spi_message msg; 160 struct spi_transfer xfer[6]; 161 162 /* 163 * DMA (thus cache coherency maintenance) requires the 164 * transfer buffers to live in their own cache lines. 165 */ 166 u16 sample ____cacheline_aligned; 167 }; 168 169 struct ad7877 { 170 struct input_dev *input; 171 char phys[32]; 172 173 struct spi_device *spi; 174 u16 model; 175 u16 vref_delay_usecs; 176 u16 x_plate_ohms; 177 u16 pressure_max; 178 179 u16 cmd_crtl1; 180 u16 cmd_crtl2; 181 u16 cmd_dummy; 182 u16 dac; 183 184 u8 stopacq_polarity; 185 u8 first_conversion_delay; 186 u8 acquisition_time; 187 u8 averaging; 188 u8 pen_down_acc_interval; 189 190 struct spi_transfer xfer[AD7877_NR_SENSE + 2]; 191 struct spi_message msg; 192 193 struct mutex mutex; 194 bool disabled; /* P: mutex */ 195 bool gpio3; /* P: mutex */ 196 bool gpio4; /* P: mutex */ 197 198 spinlock_t lock; 199 struct timer_list timer; /* P: lock */ 200 201 /* 202 * DMA (thus cache coherency maintenance) requires the 203 * transfer buffers to live in their own cache lines. 204 */ 205 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned; 206 }; 207 208 static bool gpio3; 209 module_param(gpio3, bool, 0); 210 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3"); 211 212 /* 213 * ad7877_read/write are only used for initial setup and for sysfs controls. 214 * The main traffic is done using spi_async() in the interrupt handler. 215 */ 216 217 static int ad7877_read(struct spi_device *spi, u16 reg) 218 { 219 struct ser_req *req; 220 int status, ret; 221 222 req = kzalloc(sizeof *req, GFP_KERNEL); 223 if (!req) 224 return -ENOMEM; 225 226 spi_message_init(&req->msg); 227 228 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) | 229 AD7877_READADD(reg)); 230 req->xfer[0].tx_buf = &req->command; 231 req->xfer[0].len = 2; 232 req->xfer[0].cs_change = 1; 233 234 req->xfer[1].rx_buf = &req->sample; 235 req->xfer[1].len = 2; 236 237 spi_message_add_tail(&req->xfer[0], &req->msg); 238 spi_message_add_tail(&req->xfer[1], &req->msg); 239 240 status = spi_sync(spi, &req->msg); 241 ret = status ? : req->sample; 242 243 kfree(req); 244 245 return ret; 246 } 247 248 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val) 249 { 250 struct ser_req *req; 251 int status; 252 253 req = kzalloc(sizeof *req, GFP_KERNEL); 254 if (!req) 255 return -ENOMEM; 256 257 spi_message_init(&req->msg); 258 259 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT)); 260 req->xfer[0].tx_buf = &req->command; 261 req->xfer[0].len = 2; 262 263 spi_message_add_tail(&req->xfer[0], &req->msg); 264 265 status = spi_sync(spi, &req->msg); 266 267 kfree(req); 268 269 return status; 270 } 271 272 static int ad7877_read_adc(struct spi_device *spi, unsigned command) 273 { 274 struct ad7877 *ts = dev_get_drvdata(&spi->dev); 275 struct ser_req *req; 276 int status; 277 int sample; 278 int i; 279 280 req = kzalloc(sizeof *req, GFP_KERNEL); 281 if (!req) 282 return -ENOMEM; 283 284 spi_message_init(&req->msg); 285 286 /* activate reference, so it has time to settle; */ 287 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) | 288 AD7877_POL(ts->stopacq_polarity) | 289 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) | 290 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0); 291 292 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC; 293 294 req->command = (u16) command; 295 296 req->xfer[0].tx_buf = &req->reset; 297 req->xfer[0].len = 2; 298 req->xfer[0].cs_change = 1; 299 300 req->xfer[1].tx_buf = &req->ref_on; 301 req->xfer[1].len = 2; 302 req->xfer[1].delay_usecs = ts->vref_delay_usecs; 303 req->xfer[1].cs_change = 1; 304 305 req->xfer[2].tx_buf = &req->command; 306 req->xfer[2].len = 2; 307 req->xfer[2].delay_usecs = ts->vref_delay_usecs; 308 req->xfer[2].cs_change = 1; 309 310 req->xfer[3].rx_buf = &req->sample; 311 req->xfer[3].len = 2; 312 req->xfer[3].cs_change = 1; 313 314 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ 315 req->xfer[4].len = 2; 316 req->xfer[4].cs_change = 1; 317 318 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ 319 req->xfer[5].len = 2; 320 321 /* group all the transfers together, so we can't interfere with 322 * reading touchscreen state; disable penirq while sampling 323 */ 324 for (i = 0; i < 6; i++) 325 spi_message_add_tail(&req->xfer[i], &req->msg); 326 327 status = spi_sync(spi, &req->msg); 328 sample = req->sample; 329 330 kfree(req); 331 332 return status ? : sample; 333 } 334 335 static int ad7877_process_data(struct ad7877 *ts) 336 { 337 struct input_dev *input_dev = ts->input; 338 unsigned Rt; 339 u16 x, y, z1, z2; 340 341 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT; 342 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT; 343 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT; 344 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT; 345 346 /* 347 * The samples processed here are already preprocessed by the AD7877. 348 * The preprocessing function consists of an averaging filter. 349 * The combination of 'first conversion delay' and averaging provides a robust solution, 350 * discarding the spurious noise in the signal and keeping only the data of interest. 351 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h) 352 * Other user-programmable conversion controls include variable acquisition time, 353 * and first conversion delay. Up to 16 averages can be taken per conversion. 354 */ 355 356 if (likely(x && z1)) { 357 /* compute touch pressure resistance using equation #1 */ 358 Rt = (z2 - z1) * x * ts->x_plate_ohms; 359 Rt /= z1; 360 Rt = (Rt + 2047) >> 12; 361 362 /* 363 * Sample found inconsistent, pressure is beyond 364 * the maximum. Don't report it to user space. 365 */ 366 if (Rt > ts->pressure_max) 367 return -EINVAL; 368 369 if (!timer_pending(&ts->timer)) 370 input_report_key(input_dev, BTN_TOUCH, 1); 371 372 input_report_abs(input_dev, ABS_X, x); 373 input_report_abs(input_dev, ABS_Y, y); 374 input_report_abs(input_dev, ABS_PRESSURE, Rt); 375 input_sync(input_dev); 376 377 return 0; 378 } 379 380 return -EINVAL; 381 } 382 383 static inline void ad7877_ts_event_release(struct ad7877 *ts) 384 { 385 struct input_dev *input_dev = ts->input; 386 387 input_report_abs(input_dev, ABS_PRESSURE, 0); 388 input_report_key(input_dev, BTN_TOUCH, 0); 389 input_sync(input_dev); 390 } 391 392 static void ad7877_timer(unsigned long handle) 393 { 394 struct ad7877 *ts = (void *)handle; 395 unsigned long flags; 396 397 spin_lock_irqsave(&ts->lock, flags); 398 ad7877_ts_event_release(ts); 399 spin_unlock_irqrestore(&ts->lock, flags); 400 } 401 402 static irqreturn_t ad7877_irq(int irq, void *handle) 403 { 404 struct ad7877 *ts = handle; 405 unsigned long flags; 406 int error; 407 408 error = spi_sync(ts->spi, &ts->msg); 409 if (error) { 410 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 411 goto out; 412 } 413 414 spin_lock_irqsave(&ts->lock, flags); 415 error = ad7877_process_data(ts); 416 if (!error) 417 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 418 spin_unlock_irqrestore(&ts->lock, flags); 419 420 out: 421 return IRQ_HANDLED; 422 } 423 424 static void ad7877_disable(struct ad7877 *ts) 425 { 426 mutex_lock(&ts->mutex); 427 428 if (!ts->disabled) { 429 ts->disabled = true; 430 disable_irq(ts->spi->irq); 431 432 if (del_timer_sync(&ts->timer)) 433 ad7877_ts_event_release(ts); 434 } 435 436 /* 437 * We know the chip's in lowpower mode since we always 438 * leave it that way after every request 439 */ 440 441 mutex_unlock(&ts->mutex); 442 } 443 444 static void ad7877_enable(struct ad7877 *ts) 445 { 446 mutex_lock(&ts->mutex); 447 448 if (ts->disabled) { 449 ts->disabled = false; 450 enable_irq(ts->spi->irq); 451 } 452 453 mutex_unlock(&ts->mutex); 454 } 455 456 #define SHOW(name) static ssize_t \ 457 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 458 { \ 459 struct ad7877 *ts = dev_get_drvdata(dev); \ 460 ssize_t v = ad7877_read_adc(ts->spi, \ 461 AD7877_READ_CHAN(name)); \ 462 if (v < 0) \ 463 return v; \ 464 return sprintf(buf, "%u\n", (unsigned) v); \ 465 } \ 466 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 467 468 SHOW(aux1) 469 SHOW(aux2) 470 SHOW(aux3) 471 SHOW(bat1) 472 SHOW(bat2) 473 SHOW(temp1) 474 SHOW(temp2) 475 476 static ssize_t ad7877_disable_show(struct device *dev, 477 struct device_attribute *attr, char *buf) 478 { 479 struct ad7877 *ts = dev_get_drvdata(dev); 480 481 return sprintf(buf, "%u\n", ts->disabled); 482 } 483 484 static ssize_t ad7877_disable_store(struct device *dev, 485 struct device_attribute *attr, 486 const char *buf, size_t count) 487 { 488 struct ad7877 *ts = dev_get_drvdata(dev); 489 unsigned long val; 490 int error; 491 492 error = strict_strtoul(buf, 10, &val); 493 if (error) 494 return error; 495 496 if (val) 497 ad7877_disable(ts); 498 else 499 ad7877_enable(ts); 500 501 return count; 502 } 503 504 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store); 505 506 static ssize_t ad7877_dac_show(struct device *dev, 507 struct device_attribute *attr, char *buf) 508 { 509 struct ad7877 *ts = dev_get_drvdata(dev); 510 511 return sprintf(buf, "%u\n", ts->dac); 512 } 513 514 static ssize_t ad7877_dac_store(struct device *dev, 515 struct device_attribute *attr, 516 const char *buf, size_t count) 517 { 518 struct ad7877 *ts = dev_get_drvdata(dev); 519 unsigned long val; 520 int error; 521 522 error = strict_strtoul(buf, 10, &val); 523 if (error) 524 return error; 525 526 mutex_lock(&ts->mutex); 527 ts->dac = val & 0xFF; 528 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF); 529 mutex_unlock(&ts->mutex); 530 531 return count; 532 } 533 534 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store); 535 536 static ssize_t ad7877_gpio3_show(struct device *dev, 537 struct device_attribute *attr, char *buf) 538 { 539 struct ad7877 *ts = dev_get_drvdata(dev); 540 541 return sprintf(buf, "%u\n", ts->gpio3); 542 } 543 544 static ssize_t ad7877_gpio3_store(struct device *dev, 545 struct device_attribute *attr, 546 const char *buf, size_t count) 547 { 548 struct ad7877 *ts = dev_get_drvdata(dev); 549 unsigned long val; 550 int error; 551 552 error = strict_strtoul(buf, 10, &val); 553 if (error) 554 return error; 555 556 mutex_lock(&ts->mutex); 557 ts->gpio3 = !!val; 558 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 559 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 560 mutex_unlock(&ts->mutex); 561 562 return count; 563 } 564 565 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store); 566 567 static ssize_t ad7877_gpio4_show(struct device *dev, 568 struct device_attribute *attr, char *buf) 569 { 570 struct ad7877 *ts = dev_get_drvdata(dev); 571 572 return sprintf(buf, "%u\n", ts->gpio4); 573 } 574 575 static ssize_t ad7877_gpio4_store(struct device *dev, 576 struct device_attribute *attr, 577 const char *buf, size_t count) 578 { 579 struct ad7877 *ts = dev_get_drvdata(dev); 580 unsigned long val; 581 int error; 582 583 error = strict_strtoul(buf, 10, &val); 584 if (error) 585 return error; 586 587 mutex_lock(&ts->mutex); 588 ts->gpio4 = !!val; 589 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 590 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 591 mutex_unlock(&ts->mutex); 592 593 return count; 594 } 595 596 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store); 597 598 static struct attribute *ad7877_attributes[] = { 599 &dev_attr_temp1.attr, 600 &dev_attr_temp2.attr, 601 &dev_attr_aux1.attr, 602 &dev_attr_aux2.attr, 603 &dev_attr_aux3.attr, 604 &dev_attr_bat1.attr, 605 &dev_attr_bat2.attr, 606 &dev_attr_disable.attr, 607 &dev_attr_dac.attr, 608 &dev_attr_gpio3.attr, 609 &dev_attr_gpio4.attr, 610 NULL 611 }; 612 613 static mode_t ad7877_attr_is_visible(struct kobject *kobj, 614 struct attribute *attr, int n) 615 { 616 mode_t mode = attr->mode; 617 618 if (attr == &dev_attr_aux3.attr) { 619 if (gpio3) 620 mode = 0; 621 } else if (attr == &dev_attr_gpio3.attr) { 622 if (!gpio3) 623 mode = 0; 624 } 625 626 return mode; 627 } 628 629 static const struct attribute_group ad7877_attr_group = { 630 .is_visible = ad7877_attr_is_visible, 631 .attrs = ad7877_attributes, 632 }; 633 634 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts) 635 { 636 struct spi_message *m; 637 int i; 638 639 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) | 640 AD7877_POL(ts->stopacq_polarity) | 641 AD7877_AVG(ts->averaging) | AD7877_PM(1) | 642 AD7877_TMR(ts->pen_down_acc_interval) | 643 AD7877_ACQ(ts->acquisition_time) | 644 AD7877_FCD(ts->first_conversion_delay); 645 646 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2); 647 648 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) | 649 AD7877_READADD(AD7877_REG_XPLUS-1) | 650 AD7877_MODE_SEQ1 | AD7877_DFR; 651 652 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1); 653 654 ts->cmd_dummy = 0; 655 656 m = &ts->msg; 657 658 spi_message_init(m); 659 660 m->context = ts; 661 662 ts->xfer[0].tx_buf = &ts->cmd_crtl1; 663 ts->xfer[0].len = 2; 664 ts->xfer[0].cs_change = 1; 665 666 spi_message_add_tail(&ts->xfer[0], m); 667 668 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */ 669 ts->xfer[1].len = 2; 670 ts->xfer[1].cs_change = 1; 671 672 spi_message_add_tail(&ts->xfer[1], m); 673 674 for (i = 0; i < AD7877_NR_SENSE; i++) { 675 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i]; 676 ts->xfer[i + 2].len = 2; 677 if (i < (AD7877_NR_SENSE - 1)) 678 ts->xfer[i + 2].cs_change = 1; 679 spi_message_add_tail(&ts->xfer[i + 2], m); 680 } 681 } 682 683 static int __devinit ad7877_probe(struct spi_device *spi) 684 { 685 struct ad7877 *ts; 686 struct input_dev *input_dev; 687 struct ad7877_platform_data *pdata = spi->dev.platform_data; 688 int err; 689 u16 verify; 690 691 if (!spi->irq) { 692 dev_dbg(&spi->dev, "no IRQ?\n"); 693 return -ENODEV; 694 } 695 696 if (!pdata) { 697 dev_dbg(&spi->dev, "no platform data?\n"); 698 return -ENODEV; 699 } 700 701 /* don't exceed max specified SPI CLK frequency */ 702 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 703 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz); 704 return -EINVAL; 705 } 706 707 spi->bits_per_word = 16; 708 err = spi_setup(spi); 709 if (err) { 710 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n"); 711 return err; 712 } 713 714 ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL); 715 input_dev = input_allocate_device(); 716 if (!ts || !input_dev) { 717 err = -ENOMEM; 718 goto err_free_mem; 719 } 720 721 dev_set_drvdata(&spi->dev, ts); 722 ts->spi = spi; 723 ts->input = input_dev; 724 725 setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts); 726 mutex_init(&ts->mutex); 727 spin_lock_init(&ts->lock); 728 729 ts->model = pdata->model ? : 7877; 730 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 731 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 732 ts->pressure_max = pdata->pressure_max ? : ~0; 733 734 ts->stopacq_polarity = pdata->stopacq_polarity; 735 ts->first_conversion_delay = pdata->first_conversion_delay; 736 ts->acquisition_time = pdata->acquisition_time; 737 ts->averaging = pdata->averaging; 738 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 739 740 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 741 742 input_dev->name = "AD7877 Touchscreen"; 743 input_dev->phys = ts->phys; 744 input_dev->dev.parent = &spi->dev; 745 746 __set_bit(EV_KEY, input_dev->evbit); 747 __set_bit(BTN_TOUCH, input_dev->keybit); 748 __set_bit(EV_ABS, input_dev->evbit); 749 __set_bit(ABS_X, input_dev->absbit); 750 __set_bit(ABS_Y, input_dev->absbit); 751 __set_bit(ABS_PRESSURE, input_dev->absbit); 752 753 input_set_abs_params(input_dev, ABS_X, 754 pdata->x_min ? : 0, 755 pdata->x_max ? : MAX_12BIT, 756 0, 0); 757 input_set_abs_params(input_dev, ABS_Y, 758 pdata->y_min ? : 0, 759 pdata->y_max ? : MAX_12BIT, 760 0, 0); 761 input_set_abs_params(input_dev, ABS_PRESSURE, 762 pdata->pressure_min, pdata->pressure_max, 0, 0); 763 764 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE); 765 766 verify = ad7877_read(spi, AD7877_REG_SEQ1); 767 768 if (verify != AD7877_MM_SEQUENCE){ 769 dev_err(&spi->dev, "%s: Failed to probe %s\n", 770 dev_name(&spi->dev), input_dev->name); 771 err = -ENODEV; 772 goto err_free_mem; 773 } 774 775 if (gpio3) 776 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF); 777 778 ad7877_setup_ts_def_msg(spi, ts); 779 780 /* Request AD7877 /DAV GPIO interrupt */ 781 782 err = request_threaded_irq(spi->irq, NULL, ad7877_irq, 783 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 784 spi->dev.driver->name, ts); 785 if (err) { 786 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 787 goto err_free_mem; 788 } 789 790 err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group); 791 if (err) 792 goto err_free_irq; 793 794 err = input_register_device(input_dev); 795 if (err) 796 goto err_remove_attr_group; 797 798 return 0; 799 800 err_remove_attr_group: 801 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group); 802 err_free_irq: 803 free_irq(spi->irq, ts); 804 err_free_mem: 805 input_free_device(input_dev); 806 kfree(ts); 807 dev_set_drvdata(&spi->dev, NULL); 808 return err; 809 } 810 811 static int __devexit ad7877_remove(struct spi_device *spi) 812 { 813 struct ad7877 *ts = dev_get_drvdata(&spi->dev); 814 815 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group); 816 817 ad7877_disable(ts); 818 free_irq(ts->spi->irq, ts); 819 820 input_unregister_device(ts->input); 821 kfree(ts); 822 823 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 824 dev_set_drvdata(&spi->dev, NULL); 825 826 return 0; 827 } 828 829 #ifdef CONFIG_PM 830 static int ad7877_suspend(struct spi_device *spi, pm_message_t message) 831 { 832 struct ad7877 *ts = dev_get_drvdata(&spi->dev); 833 834 ad7877_disable(ts); 835 836 return 0; 837 } 838 839 static int ad7877_resume(struct spi_device *spi) 840 { 841 struct ad7877 *ts = dev_get_drvdata(&spi->dev); 842 843 ad7877_enable(ts); 844 845 return 0; 846 } 847 #else 848 #define ad7877_suspend NULL 849 #define ad7877_resume NULL 850 #endif 851 852 static struct spi_driver ad7877_driver = { 853 .driver = { 854 .name = "ad7877", 855 .bus = &spi_bus_type, 856 .owner = THIS_MODULE, 857 }, 858 .probe = ad7877_probe, 859 .remove = __devexit_p(ad7877_remove), 860 .suspend = ad7877_suspend, 861 .resume = ad7877_resume, 862 }; 863 864 static int __init ad7877_init(void) 865 { 866 return spi_register_driver(&ad7877_driver); 867 } 868 module_init(ad7877_init); 869 870 static void __exit ad7877_exit(void) 871 { 872 spi_unregister_driver(&ad7877_driver); 873 } 874 module_exit(ad7877_exit); 875 876 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 877 MODULE_DESCRIPTION("AD7877 touchscreen Driver"); 878 MODULE_LICENSE("GPL"); 879 MODULE_ALIAS("spi:ad7877"); 880