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/delay.h> 41 #include <linux/input.h> 42 #include <linux/interrupt.h> 43 #include <linux/pm.h> 44 #include <linux/slab.h> 45 #include <linux/spi/spi.h> 46 #include <linux/spi/ad7877.h> 47 #include <linux/module.h> 48 #include <asm/irq.h> 49 50 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100) 51 52 #define MAX_SPI_FREQ_HZ 20000000 53 #define MAX_12BIT ((1<<12)-1) 54 55 #define AD7877_REG_ZEROS 0 56 #define AD7877_REG_CTRL1 1 57 #define AD7877_REG_CTRL2 2 58 #define AD7877_REG_ALERT 3 59 #define AD7877_REG_AUX1HIGH 4 60 #define AD7877_REG_AUX1LOW 5 61 #define AD7877_REG_BAT1HIGH 6 62 #define AD7877_REG_BAT1LOW 7 63 #define AD7877_REG_BAT2HIGH 8 64 #define AD7877_REG_BAT2LOW 9 65 #define AD7877_REG_TEMP1HIGH 10 66 #define AD7877_REG_TEMP1LOW 11 67 #define AD7877_REG_SEQ0 12 68 #define AD7877_REG_SEQ1 13 69 #define AD7877_REG_DAC 14 70 #define AD7877_REG_NONE1 15 71 #define AD7877_REG_EXTWRITE 15 72 #define AD7877_REG_XPLUS 16 73 #define AD7877_REG_YPLUS 17 74 #define AD7877_REG_Z2 18 75 #define AD7877_REG_aux1 19 76 #define AD7877_REG_aux2 20 77 #define AD7877_REG_aux3 21 78 #define AD7877_REG_bat1 22 79 #define AD7877_REG_bat2 23 80 #define AD7877_REG_temp1 24 81 #define AD7877_REG_temp2 25 82 #define AD7877_REG_Z1 26 83 #define AD7877_REG_GPIOCTRL1 27 84 #define AD7877_REG_GPIOCTRL2 28 85 #define AD7877_REG_GPIODATA 29 86 #define AD7877_REG_NONE2 30 87 #define AD7877_REG_NONE3 31 88 89 #define AD7877_SEQ_YPLUS_BIT (1<<11) 90 #define AD7877_SEQ_XPLUS_BIT (1<<10) 91 #define AD7877_SEQ_Z2_BIT (1<<9) 92 #define AD7877_SEQ_AUX1_BIT (1<<8) 93 #define AD7877_SEQ_AUX2_BIT (1<<7) 94 #define AD7877_SEQ_AUX3_BIT (1<<6) 95 #define AD7877_SEQ_BAT1_BIT (1<<5) 96 #define AD7877_SEQ_BAT2_BIT (1<<4) 97 #define AD7877_SEQ_TEMP1_BIT (1<<3) 98 #define AD7877_SEQ_TEMP2_BIT (1<<2) 99 #define AD7877_SEQ_Z1_BIT (1<<1) 100 101 enum { 102 AD7877_SEQ_YPOS = 0, 103 AD7877_SEQ_XPOS = 1, 104 AD7877_SEQ_Z2 = 2, 105 AD7877_SEQ_AUX1 = 3, 106 AD7877_SEQ_AUX2 = 4, 107 AD7877_SEQ_AUX3 = 5, 108 AD7877_SEQ_BAT1 = 6, 109 AD7877_SEQ_BAT2 = 7, 110 AD7877_SEQ_TEMP1 = 8, 111 AD7877_SEQ_TEMP2 = 9, 112 AD7877_SEQ_Z1 = 10, 113 AD7877_NR_SENSE = 11, 114 }; 115 116 /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */ 117 #define AD7877_DAC_CONF 0x1 118 119 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */ 120 #define AD7877_EXTW_GPIO_3_CONF 0x1C4 121 #define AD7877_EXTW_GPIO_DATA 0x200 122 123 /* Control REG 2 */ 124 #define AD7877_TMR(x) ((x & 0x3) << 0) 125 #define AD7877_REF(x) ((x & 0x1) << 2) 126 #define AD7877_POL(x) ((x & 0x1) << 3) 127 #define AD7877_FCD(x) ((x & 0x3) << 4) 128 #define AD7877_PM(x) ((x & 0x3) << 6) 129 #define AD7877_ACQ(x) ((x & 0x3) << 8) 130 #define AD7877_AVG(x) ((x & 0x3) << 10) 131 132 /* Control REG 1 */ 133 #define AD7877_SER (1 << 11) /* non-differential */ 134 #define AD7877_DFR (0 << 11) /* differential */ 135 136 #define AD7877_MODE_NOC (0) /* Do not convert */ 137 #define AD7877_MODE_SCC (1) /* Single channel conversion */ 138 #define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */ 139 #define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */ 140 141 #define AD7877_CHANADD(x) ((x&0xF)<<7) 142 #define AD7877_READADD(x) ((x)<<2) 143 #define AD7877_WRITEADD(x) ((x)<<12) 144 145 #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \ 146 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \ 147 AD7877_READADD(AD7877_REG_ ## x)) 148 149 #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \ 150 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT) 151 152 /* 153 * Non-touchscreen sensors only use single-ended conversions. 154 */ 155 156 struct ser_req { 157 u16 reset; 158 u16 ref_on; 159 u16 command; 160 struct spi_message msg; 161 struct spi_transfer xfer[6]; 162 163 /* 164 * DMA (thus cache coherency maintenance) requires the 165 * transfer buffers to live in their own cache lines. 166 */ 167 u16 sample ____cacheline_aligned; 168 }; 169 170 struct ad7877 { 171 struct input_dev *input; 172 char phys[32]; 173 174 struct spi_device *spi; 175 u16 model; 176 u16 vref_delay_usecs; 177 u16 x_plate_ohms; 178 u16 pressure_max; 179 180 u16 cmd_crtl1; 181 u16 cmd_crtl2; 182 u16 cmd_dummy; 183 u16 dac; 184 185 u8 stopacq_polarity; 186 u8 first_conversion_delay; 187 u8 acquisition_time; 188 u8 averaging; 189 u8 pen_down_acc_interval; 190 191 struct spi_transfer xfer[AD7877_NR_SENSE + 2]; 192 struct spi_message msg; 193 194 struct mutex mutex; 195 bool disabled; /* P: mutex */ 196 bool gpio3; /* P: mutex */ 197 bool gpio4; /* P: mutex */ 198 199 spinlock_t lock; 200 struct timer_list timer; /* P: lock */ 201 202 /* 203 * DMA (thus cache coherency maintenance) requires the 204 * transfer buffers to live in their own cache lines. 205 */ 206 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned; 207 }; 208 209 static bool gpio3; 210 module_param(gpio3, bool, 0); 211 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3"); 212 213 /* 214 * ad7877_read/write are only used for initial setup and for sysfs controls. 215 * The main traffic is done using spi_async() in the interrupt handler. 216 */ 217 218 static int ad7877_read(struct spi_device *spi, u16 reg) 219 { 220 struct ser_req *req; 221 int status, ret; 222 223 req = kzalloc(sizeof *req, GFP_KERNEL); 224 if (!req) 225 return -ENOMEM; 226 227 spi_message_init(&req->msg); 228 229 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) | 230 AD7877_READADD(reg)); 231 req->xfer[0].tx_buf = &req->command; 232 req->xfer[0].len = 2; 233 req->xfer[0].cs_change = 1; 234 235 req->xfer[1].rx_buf = &req->sample; 236 req->xfer[1].len = 2; 237 238 spi_message_add_tail(&req->xfer[0], &req->msg); 239 spi_message_add_tail(&req->xfer[1], &req->msg); 240 241 status = spi_sync(spi, &req->msg); 242 ret = status ? : req->sample; 243 244 kfree(req); 245 246 return ret; 247 } 248 249 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val) 250 { 251 struct ser_req *req; 252 int status; 253 254 req = kzalloc(sizeof *req, GFP_KERNEL); 255 if (!req) 256 return -ENOMEM; 257 258 spi_message_init(&req->msg); 259 260 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT)); 261 req->xfer[0].tx_buf = &req->command; 262 req->xfer[0].len = 2; 263 264 spi_message_add_tail(&req->xfer[0], &req->msg); 265 266 status = spi_sync(spi, &req->msg); 267 268 kfree(req); 269 270 return status; 271 } 272 273 static int ad7877_read_adc(struct spi_device *spi, unsigned command) 274 { 275 struct ad7877 *ts = spi_get_drvdata(spi); 276 struct ser_req *req; 277 int status; 278 int sample; 279 int i; 280 281 req = kzalloc(sizeof *req, GFP_KERNEL); 282 if (!req) 283 return -ENOMEM; 284 285 spi_message_init(&req->msg); 286 287 /* activate reference, so it has time to settle; */ 288 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) | 289 AD7877_POL(ts->stopacq_polarity) | 290 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) | 291 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0); 292 293 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC; 294 295 req->command = (u16) command; 296 297 req->xfer[0].tx_buf = &req->reset; 298 req->xfer[0].len = 2; 299 req->xfer[0].cs_change = 1; 300 301 req->xfer[1].tx_buf = &req->ref_on; 302 req->xfer[1].len = 2; 303 req->xfer[1].delay_usecs = ts->vref_delay_usecs; 304 req->xfer[1].cs_change = 1; 305 306 req->xfer[2].tx_buf = &req->command; 307 req->xfer[2].len = 2; 308 req->xfer[2].delay_usecs = ts->vref_delay_usecs; 309 req->xfer[2].cs_change = 1; 310 311 req->xfer[3].rx_buf = &req->sample; 312 req->xfer[3].len = 2; 313 req->xfer[3].cs_change = 1; 314 315 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ 316 req->xfer[4].len = 2; 317 req->xfer[4].cs_change = 1; 318 319 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ 320 req->xfer[5].len = 2; 321 322 /* group all the transfers together, so we can't interfere with 323 * reading touchscreen state; disable penirq while sampling 324 */ 325 for (i = 0; i < 6; i++) 326 spi_message_add_tail(&req->xfer[i], &req->msg); 327 328 status = spi_sync(spi, &req->msg); 329 sample = req->sample; 330 331 kfree(req); 332 333 return status ? : sample; 334 } 335 336 static int ad7877_process_data(struct ad7877 *ts) 337 { 338 struct input_dev *input_dev = ts->input; 339 unsigned Rt; 340 u16 x, y, z1, z2; 341 342 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT; 343 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT; 344 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT; 345 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT; 346 347 /* 348 * The samples processed here are already preprocessed by the AD7877. 349 * The preprocessing function consists of an averaging filter. 350 * The combination of 'first conversion delay' and averaging provides a robust solution, 351 * discarding the spurious noise in the signal and keeping only the data of interest. 352 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h) 353 * Other user-programmable conversion controls include variable acquisition time, 354 * and first conversion delay. Up to 16 averages can be taken per conversion. 355 */ 356 357 if (likely(x && z1)) { 358 /* compute touch pressure resistance using equation #1 */ 359 Rt = (z2 - z1) * x * ts->x_plate_ohms; 360 Rt /= z1; 361 Rt = (Rt + 2047) >> 12; 362 363 /* 364 * Sample found inconsistent, pressure is beyond 365 * the maximum. Don't report it to user space. 366 */ 367 if (Rt > ts->pressure_max) 368 return -EINVAL; 369 370 if (!timer_pending(&ts->timer)) 371 input_report_key(input_dev, BTN_TOUCH, 1); 372 373 input_report_abs(input_dev, ABS_X, x); 374 input_report_abs(input_dev, ABS_Y, y); 375 input_report_abs(input_dev, ABS_PRESSURE, Rt); 376 input_sync(input_dev); 377 378 return 0; 379 } 380 381 return -EINVAL; 382 } 383 384 static inline void ad7877_ts_event_release(struct ad7877 *ts) 385 { 386 struct input_dev *input_dev = ts->input; 387 388 input_report_abs(input_dev, ABS_PRESSURE, 0); 389 input_report_key(input_dev, BTN_TOUCH, 0); 390 input_sync(input_dev); 391 } 392 393 static void ad7877_timer(unsigned long handle) 394 { 395 struct ad7877 *ts = (void *)handle; 396 unsigned long flags; 397 398 spin_lock_irqsave(&ts->lock, flags); 399 ad7877_ts_event_release(ts); 400 spin_unlock_irqrestore(&ts->lock, flags); 401 } 402 403 static irqreturn_t ad7877_irq(int irq, void *handle) 404 { 405 struct ad7877 *ts = handle; 406 unsigned long flags; 407 int error; 408 409 error = spi_sync(ts->spi, &ts->msg); 410 if (error) { 411 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 412 goto out; 413 } 414 415 spin_lock_irqsave(&ts->lock, flags); 416 error = ad7877_process_data(ts); 417 if (!error) 418 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 419 spin_unlock_irqrestore(&ts->lock, flags); 420 421 out: 422 return IRQ_HANDLED; 423 } 424 425 static void ad7877_disable(struct ad7877 *ts) 426 { 427 mutex_lock(&ts->mutex); 428 429 if (!ts->disabled) { 430 ts->disabled = true; 431 disable_irq(ts->spi->irq); 432 433 if (del_timer_sync(&ts->timer)) 434 ad7877_ts_event_release(ts); 435 } 436 437 /* 438 * We know the chip's in lowpower mode since we always 439 * leave it that way after every request 440 */ 441 442 mutex_unlock(&ts->mutex); 443 } 444 445 static void ad7877_enable(struct ad7877 *ts) 446 { 447 mutex_lock(&ts->mutex); 448 449 if (ts->disabled) { 450 ts->disabled = false; 451 enable_irq(ts->spi->irq); 452 } 453 454 mutex_unlock(&ts->mutex); 455 } 456 457 #define SHOW(name) static ssize_t \ 458 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 459 { \ 460 struct ad7877 *ts = dev_get_drvdata(dev); \ 461 ssize_t v = ad7877_read_adc(ts->spi, \ 462 AD7877_READ_CHAN(name)); \ 463 if (v < 0) \ 464 return v; \ 465 return sprintf(buf, "%u\n", (unsigned) v); \ 466 } \ 467 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 468 469 SHOW(aux1) 470 SHOW(aux2) 471 SHOW(aux3) 472 SHOW(bat1) 473 SHOW(bat2) 474 SHOW(temp1) 475 SHOW(temp2) 476 477 static ssize_t ad7877_disable_show(struct device *dev, 478 struct device_attribute *attr, char *buf) 479 { 480 struct ad7877 *ts = dev_get_drvdata(dev); 481 482 return sprintf(buf, "%u\n", ts->disabled); 483 } 484 485 static ssize_t ad7877_disable_store(struct device *dev, 486 struct device_attribute *attr, 487 const char *buf, size_t count) 488 { 489 struct ad7877 *ts = dev_get_drvdata(dev); 490 unsigned int val; 491 int error; 492 493 error = kstrtouint(buf, 10, &val); 494 if (error) 495 return error; 496 497 if (val) 498 ad7877_disable(ts); 499 else 500 ad7877_enable(ts); 501 502 return count; 503 } 504 505 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store); 506 507 static ssize_t ad7877_dac_show(struct device *dev, 508 struct device_attribute *attr, char *buf) 509 { 510 struct ad7877 *ts = dev_get_drvdata(dev); 511 512 return sprintf(buf, "%u\n", ts->dac); 513 } 514 515 static ssize_t ad7877_dac_store(struct device *dev, 516 struct device_attribute *attr, 517 const char *buf, size_t count) 518 { 519 struct ad7877 *ts = dev_get_drvdata(dev); 520 unsigned int val; 521 int error; 522 523 error = kstrtouint(buf, 10, &val); 524 if (error) 525 return error; 526 527 mutex_lock(&ts->mutex); 528 ts->dac = val & 0xFF; 529 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF); 530 mutex_unlock(&ts->mutex); 531 532 return count; 533 } 534 535 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store); 536 537 static ssize_t ad7877_gpio3_show(struct device *dev, 538 struct device_attribute *attr, char *buf) 539 { 540 struct ad7877 *ts = dev_get_drvdata(dev); 541 542 return sprintf(buf, "%u\n", ts->gpio3); 543 } 544 545 static ssize_t ad7877_gpio3_store(struct device *dev, 546 struct device_attribute *attr, 547 const char *buf, size_t count) 548 { 549 struct ad7877 *ts = dev_get_drvdata(dev); 550 unsigned int val; 551 int error; 552 553 error = kstrtouint(buf, 10, &val); 554 if (error) 555 return error; 556 557 mutex_lock(&ts->mutex); 558 ts->gpio3 = !!val; 559 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 560 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 561 mutex_unlock(&ts->mutex); 562 563 return count; 564 } 565 566 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store); 567 568 static ssize_t ad7877_gpio4_show(struct device *dev, 569 struct device_attribute *attr, char *buf) 570 { 571 struct ad7877 *ts = dev_get_drvdata(dev); 572 573 return sprintf(buf, "%u\n", ts->gpio4); 574 } 575 576 static ssize_t ad7877_gpio4_store(struct device *dev, 577 struct device_attribute *attr, 578 const char *buf, size_t count) 579 { 580 struct ad7877 *ts = dev_get_drvdata(dev); 581 unsigned int val; 582 int error; 583 584 error = kstrtouint(buf, 10, &val); 585 if (error) 586 return error; 587 588 mutex_lock(&ts->mutex); 589 ts->gpio4 = !!val; 590 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 591 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 592 mutex_unlock(&ts->mutex); 593 594 return count; 595 } 596 597 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store); 598 599 static struct attribute *ad7877_attributes[] = { 600 &dev_attr_temp1.attr, 601 &dev_attr_temp2.attr, 602 &dev_attr_aux1.attr, 603 &dev_attr_aux2.attr, 604 &dev_attr_aux3.attr, 605 &dev_attr_bat1.attr, 606 &dev_attr_bat2.attr, 607 &dev_attr_disable.attr, 608 &dev_attr_dac.attr, 609 &dev_attr_gpio3.attr, 610 &dev_attr_gpio4.attr, 611 NULL 612 }; 613 614 static umode_t ad7877_attr_is_visible(struct kobject *kobj, 615 struct attribute *attr, int n) 616 { 617 umode_t mode = attr->mode; 618 619 if (attr == &dev_attr_aux3.attr) { 620 if (gpio3) 621 mode = 0; 622 } else if (attr == &dev_attr_gpio3.attr) { 623 if (!gpio3) 624 mode = 0; 625 } 626 627 return mode; 628 } 629 630 static const struct attribute_group ad7877_attr_group = { 631 .is_visible = ad7877_attr_is_visible, 632 .attrs = ad7877_attributes, 633 }; 634 635 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts) 636 { 637 struct spi_message *m; 638 int i; 639 640 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) | 641 AD7877_POL(ts->stopacq_polarity) | 642 AD7877_AVG(ts->averaging) | AD7877_PM(1) | 643 AD7877_TMR(ts->pen_down_acc_interval) | 644 AD7877_ACQ(ts->acquisition_time) | 645 AD7877_FCD(ts->first_conversion_delay); 646 647 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2); 648 649 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) | 650 AD7877_READADD(AD7877_REG_XPLUS-1) | 651 AD7877_MODE_SEQ1 | AD7877_DFR; 652 653 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1); 654 655 ts->cmd_dummy = 0; 656 657 m = &ts->msg; 658 659 spi_message_init(m); 660 661 m->context = ts; 662 663 ts->xfer[0].tx_buf = &ts->cmd_crtl1; 664 ts->xfer[0].len = 2; 665 ts->xfer[0].cs_change = 1; 666 667 spi_message_add_tail(&ts->xfer[0], m); 668 669 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */ 670 ts->xfer[1].len = 2; 671 ts->xfer[1].cs_change = 1; 672 673 spi_message_add_tail(&ts->xfer[1], m); 674 675 for (i = 0; i < AD7877_NR_SENSE; i++) { 676 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i]; 677 ts->xfer[i + 2].len = 2; 678 if (i < (AD7877_NR_SENSE - 1)) 679 ts->xfer[i + 2].cs_change = 1; 680 spi_message_add_tail(&ts->xfer[i + 2], m); 681 } 682 } 683 684 static int ad7877_probe(struct spi_device *spi) 685 { 686 struct ad7877 *ts; 687 struct input_dev *input_dev; 688 struct ad7877_platform_data *pdata = dev_get_platdata(&spi->dev); 689 int err; 690 u16 verify; 691 692 if (!spi->irq) { 693 dev_dbg(&spi->dev, "no IRQ?\n"); 694 return -ENODEV; 695 } 696 697 if (!pdata) { 698 dev_dbg(&spi->dev, "no platform data?\n"); 699 return -ENODEV; 700 } 701 702 /* don't exceed max specified SPI CLK frequency */ 703 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 704 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz); 705 return -EINVAL; 706 } 707 708 spi->bits_per_word = 16; 709 err = spi_setup(spi); 710 if (err) { 711 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n"); 712 return err; 713 } 714 715 ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL); 716 input_dev = input_allocate_device(); 717 if (!ts || !input_dev) { 718 err = -ENOMEM; 719 goto err_free_mem; 720 } 721 722 spi_set_drvdata(spi, ts); 723 ts->spi = spi; 724 ts->input = input_dev; 725 726 setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts); 727 mutex_init(&ts->mutex); 728 spin_lock_init(&ts->lock); 729 730 ts->model = pdata->model ? : 7877; 731 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 732 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 733 ts->pressure_max = pdata->pressure_max ? : ~0; 734 735 ts->stopacq_polarity = pdata->stopacq_polarity; 736 ts->first_conversion_delay = pdata->first_conversion_delay; 737 ts->acquisition_time = pdata->acquisition_time; 738 ts->averaging = pdata->averaging; 739 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 740 741 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 742 743 input_dev->name = "AD7877 Touchscreen"; 744 input_dev->phys = ts->phys; 745 input_dev->dev.parent = &spi->dev; 746 747 __set_bit(EV_KEY, input_dev->evbit); 748 __set_bit(BTN_TOUCH, input_dev->keybit); 749 __set_bit(EV_ABS, input_dev->evbit); 750 __set_bit(ABS_X, input_dev->absbit); 751 __set_bit(ABS_Y, input_dev->absbit); 752 __set_bit(ABS_PRESSURE, input_dev->absbit); 753 754 input_set_abs_params(input_dev, ABS_X, 755 pdata->x_min ? : 0, 756 pdata->x_max ? : MAX_12BIT, 757 0, 0); 758 input_set_abs_params(input_dev, ABS_Y, 759 pdata->y_min ? : 0, 760 pdata->y_max ? : MAX_12BIT, 761 0, 0); 762 input_set_abs_params(input_dev, ABS_PRESSURE, 763 pdata->pressure_min, pdata->pressure_max, 0, 0); 764 765 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE); 766 767 verify = ad7877_read(spi, AD7877_REG_SEQ1); 768 769 if (verify != AD7877_MM_SEQUENCE){ 770 dev_err(&spi->dev, "%s: Failed to probe %s\n", 771 dev_name(&spi->dev), input_dev->name); 772 err = -ENODEV; 773 goto err_free_mem; 774 } 775 776 if (gpio3) 777 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF); 778 779 ad7877_setup_ts_def_msg(spi, ts); 780 781 /* Request AD7877 /DAV GPIO interrupt */ 782 783 err = request_threaded_irq(spi->irq, NULL, ad7877_irq, 784 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 785 spi->dev.driver->name, ts); 786 if (err) { 787 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 788 goto err_free_mem; 789 } 790 791 err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group); 792 if (err) 793 goto err_free_irq; 794 795 err = input_register_device(input_dev); 796 if (err) 797 goto err_remove_attr_group; 798 799 return 0; 800 801 err_remove_attr_group: 802 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group); 803 err_free_irq: 804 free_irq(spi->irq, ts); 805 err_free_mem: 806 input_free_device(input_dev); 807 kfree(ts); 808 return err; 809 } 810 811 static int ad7877_remove(struct spi_device *spi) 812 { 813 struct ad7877 *ts = spi_get_drvdata(spi); 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"); 824 825 return 0; 826 } 827 828 #ifdef CONFIG_PM_SLEEP 829 static int ad7877_suspend(struct device *dev) 830 { 831 struct ad7877 *ts = dev_get_drvdata(dev); 832 833 ad7877_disable(ts); 834 835 return 0; 836 } 837 838 static int ad7877_resume(struct device *dev) 839 { 840 struct ad7877 *ts = dev_get_drvdata(dev); 841 842 ad7877_enable(ts); 843 844 return 0; 845 } 846 #endif 847 848 static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume); 849 850 static struct spi_driver ad7877_driver = { 851 .driver = { 852 .name = "ad7877", 853 .owner = THIS_MODULE, 854 .pm = &ad7877_pm, 855 }, 856 .probe = ad7877_probe, 857 .remove = ad7877_remove, 858 }; 859 860 module_spi_driver(ad7877_driver); 861 862 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 863 MODULE_DESCRIPTION("AD7877 touchscreen Driver"); 864 MODULE_LICENSE("GPL"); 865 MODULE_ALIAS("spi:ad7877"); 866