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 static int ad7877_read(struct spi_device *spi, u16 reg) 214 { 215 struct ser_req *req; 216 int status, ret; 217 218 req = kzalloc(sizeof *req, GFP_KERNEL); 219 if (!req) 220 return -ENOMEM; 221 222 spi_message_init(&req->msg); 223 224 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) | 225 AD7877_READADD(reg)); 226 req->xfer[0].tx_buf = &req->command; 227 req->xfer[0].len = 2; 228 req->xfer[0].cs_change = 1; 229 230 req->xfer[1].rx_buf = &req->sample; 231 req->xfer[1].len = 2; 232 233 spi_message_add_tail(&req->xfer[0], &req->msg); 234 spi_message_add_tail(&req->xfer[1], &req->msg); 235 236 status = spi_sync(spi, &req->msg); 237 ret = status ? : req->sample; 238 239 kfree(req); 240 241 return ret; 242 } 243 244 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val) 245 { 246 struct ser_req *req; 247 int status; 248 249 req = kzalloc(sizeof *req, GFP_KERNEL); 250 if (!req) 251 return -ENOMEM; 252 253 spi_message_init(&req->msg); 254 255 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT)); 256 req->xfer[0].tx_buf = &req->command; 257 req->xfer[0].len = 2; 258 259 spi_message_add_tail(&req->xfer[0], &req->msg); 260 261 status = spi_sync(spi, &req->msg); 262 263 kfree(req); 264 265 return status; 266 } 267 268 static int ad7877_read_adc(struct spi_device *spi, unsigned command) 269 { 270 struct ad7877 *ts = spi_get_drvdata(spi); 271 struct ser_req *req; 272 int status; 273 int sample; 274 int i; 275 276 req = kzalloc(sizeof *req, GFP_KERNEL); 277 if (!req) 278 return -ENOMEM; 279 280 spi_message_init(&req->msg); 281 282 /* activate reference, so it has time to settle; */ 283 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) | 284 AD7877_POL(ts->stopacq_polarity) | 285 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) | 286 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0); 287 288 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC; 289 290 req->command = (u16) command; 291 292 req->xfer[0].tx_buf = &req->reset; 293 req->xfer[0].len = 2; 294 req->xfer[0].cs_change = 1; 295 296 req->xfer[1].tx_buf = &req->ref_on; 297 req->xfer[1].len = 2; 298 req->xfer[1].delay_usecs = ts->vref_delay_usecs; 299 req->xfer[1].cs_change = 1; 300 301 req->xfer[2].tx_buf = &req->command; 302 req->xfer[2].len = 2; 303 req->xfer[2].delay_usecs = ts->vref_delay_usecs; 304 req->xfer[2].cs_change = 1; 305 306 req->xfer[3].rx_buf = &req->sample; 307 req->xfer[3].len = 2; 308 req->xfer[3].cs_change = 1; 309 310 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ 311 req->xfer[4].len = 2; 312 req->xfer[4].cs_change = 1; 313 314 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ 315 req->xfer[5].len = 2; 316 317 /* group all the transfers together, so we can't interfere with 318 * reading touchscreen state; disable penirq while sampling 319 */ 320 for (i = 0; i < 6; i++) 321 spi_message_add_tail(&req->xfer[i], &req->msg); 322 323 status = spi_sync(spi, &req->msg); 324 sample = req->sample; 325 326 kfree(req); 327 328 return status ? : sample; 329 } 330 331 static int ad7877_process_data(struct ad7877 *ts) 332 { 333 struct input_dev *input_dev = ts->input; 334 unsigned Rt; 335 u16 x, y, z1, z2; 336 337 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT; 338 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT; 339 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT; 340 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT; 341 342 /* 343 * The samples processed here are already preprocessed by the AD7877. 344 * The preprocessing function consists of an averaging filter. 345 * The combination of 'first conversion delay' and averaging provides a robust solution, 346 * discarding the spurious noise in the signal and keeping only the data of interest. 347 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h) 348 * Other user-programmable conversion controls include variable acquisition time, 349 * and first conversion delay. Up to 16 averages can be taken per conversion. 350 */ 351 352 if (likely(x && z1)) { 353 /* compute touch pressure resistance using equation #1 */ 354 Rt = (z2 - z1) * x * ts->x_plate_ohms; 355 Rt /= z1; 356 Rt = (Rt + 2047) >> 12; 357 358 /* 359 * Sample found inconsistent, pressure is beyond 360 * the maximum. Don't report it to user space. 361 */ 362 if (Rt > ts->pressure_max) 363 return -EINVAL; 364 365 if (!timer_pending(&ts->timer)) 366 input_report_key(input_dev, BTN_TOUCH, 1); 367 368 input_report_abs(input_dev, ABS_X, x); 369 input_report_abs(input_dev, ABS_Y, y); 370 input_report_abs(input_dev, ABS_PRESSURE, Rt); 371 input_sync(input_dev); 372 373 return 0; 374 } 375 376 return -EINVAL; 377 } 378 379 static inline void ad7877_ts_event_release(struct ad7877 *ts) 380 { 381 struct input_dev *input_dev = ts->input; 382 383 input_report_abs(input_dev, ABS_PRESSURE, 0); 384 input_report_key(input_dev, BTN_TOUCH, 0); 385 input_sync(input_dev); 386 } 387 388 static void ad7877_timer(unsigned long handle) 389 { 390 struct ad7877 *ts = (void *)handle; 391 unsigned long flags; 392 393 spin_lock_irqsave(&ts->lock, flags); 394 ad7877_ts_event_release(ts); 395 spin_unlock_irqrestore(&ts->lock, flags); 396 } 397 398 static irqreturn_t ad7877_irq(int irq, void *handle) 399 { 400 struct ad7877 *ts = handle; 401 unsigned long flags; 402 int error; 403 404 error = spi_sync(ts->spi, &ts->msg); 405 if (error) { 406 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 407 goto out; 408 } 409 410 spin_lock_irqsave(&ts->lock, flags); 411 error = ad7877_process_data(ts); 412 if (!error) 413 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 414 spin_unlock_irqrestore(&ts->lock, flags); 415 416 out: 417 return IRQ_HANDLED; 418 } 419 420 static void ad7877_disable(struct ad7877 *ts) 421 { 422 mutex_lock(&ts->mutex); 423 424 if (!ts->disabled) { 425 ts->disabled = true; 426 disable_irq(ts->spi->irq); 427 428 if (del_timer_sync(&ts->timer)) 429 ad7877_ts_event_release(ts); 430 } 431 432 /* 433 * We know the chip's in lowpower mode since we always 434 * leave it that way after every request 435 */ 436 437 mutex_unlock(&ts->mutex); 438 } 439 440 static void ad7877_enable(struct ad7877 *ts) 441 { 442 mutex_lock(&ts->mutex); 443 444 if (ts->disabled) { 445 ts->disabled = false; 446 enable_irq(ts->spi->irq); 447 } 448 449 mutex_unlock(&ts->mutex); 450 } 451 452 #define SHOW(name) static ssize_t \ 453 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 454 { \ 455 struct ad7877 *ts = dev_get_drvdata(dev); \ 456 ssize_t v = ad7877_read_adc(ts->spi, \ 457 AD7877_READ_CHAN(name)); \ 458 if (v < 0) \ 459 return v; \ 460 return sprintf(buf, "%u\n", (unsigned) v); \ 461 } \ 462 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 463 464 SHOW(aux1) 465 SHOW(aux2) 466 SHOW(aux3) 467 SHOW(bat1) 468 SHOW(bat2) 469 SHOW(temp1) 470 SHOW(temp2) 471 472 static ssize_t ad7877_disable_show(struct device *dev, 473 struct device_attribute *attr, char *buf) 474 { 475 struct ad7877 *ts = dev_get_drvdata(dev); 476 477 return sprintf(buf, "%u\n", ts->disabled); 478 } 479 480 static ssize_t ad7877_disable_store(struct device *dev, 481 struct device_attribute *attr, 482 const char *buf, size_t count) 483 { 484 struct ad7877 *ts = dev_get_drvdata(dev); 485 unsigned int val; 486 int error; 487 488 error = kstrtouint(buf, 10, &val); 489 if (error) 490 return error; 491 492 if (val) 493 ad7877_disable(ts); 494 else 495 ad7877_enable(ts); 496 497 return count; 498 } 499 500 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store); 501 502 static ssize_t ad7877_dac_show(struct device *dev, 503 struct device_attribute *attr, char *buf) 504 { 505 struct ad7877 *ts = dev_get_drvdata(dev); 506 507 return sprintf(buf, "%u\n", ts->dac); 508 } 509 510 static ssize_t ad7877_dac_store(struct device *dev, 511 struct device_attribute *attr, 512 const char *buf, size_t count) 513 { 514 struct ad7877 *ts = dev_get_drvdata(dev); 515 unsigned int val; 516 int error; 517 518 error = kstrtouint(buf, 10, &val); 519 if (error) 520 return error; 521 522 mutex_lock(&ts->mutex); 523 ts->dac = val & 0xFF; 524 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF); 525 mutex_unlock(&ts->mutex); 526 527 return count; 528 } 529 530 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store); 531 532 static ssize_t ad7877_gpio3_show(struct device *dev, 533 struct device_attribute *attr, char *buf) 534 { 535 struct ad7877 *ts = dev_get_drvdata(dev); 536 537 return sprintf(buf, "%u\n", ts->gpio3); 538 } 539 540 static ssize_t ad7877_gpio3_store(struct device *dev, 541 struct device_attribute *attr, 542 const char *buf, size_t count) 543 { 544 struct ad7877 *ts = dev_get_drvdata(dev); 545 unsigned int val; 546 int error; 547 548 error = kstrtouint(buf, 10, &val); 549 if (error) 550 return error; 551 552 mutex_lock(&ts->mutex); 553 ts->gpio3 = !!val; 554 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 555 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 556 mutex_unlock(&ts->mutex); 557 558 return count; 559 } 560 561 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store); 562 563 static ssize_t ad7877_gpio4_show(struct device *dev, 564 struct device_attribute *attr, char *buf) 565 { 566 struct ad7877 *ts = dev_get_drvdata(dev); 567 568 return sprintf(buf, "%u\n", ts->gpio4); 569 } 570 571 static ssize_t ad7877_gpio4_store(struct device *dev, 572 struct device_attribute *attr, 573 const char *buf, size_t count) 574 { 575 struct ad7877 *ts = dev_get_drvdata(dev); 576 unsigned int val; 577 int error; 578 579 error = kstrtouint(buf, 10, &val); 580 if (error) 581 return error; 582 583 mutex_lock(&ts->mutex); 584 ts->gpio4 = !!val; 585 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 586 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 587 mutex_unlock(&ts->mutex); 588 589 return count; 590 } 591 592 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store); 593 594 static struct attribute *ad7877_attributes[] = { 595 &dev_attr_temp1.attr, 596 &dev_attr_temp2.attr, 597 &dev_attr_aux1.attr, 598 &dev_attr_aux2.attr, 599 &dev_attr_aux3.attr, 600 &dev_attr_bat1.attr, 601 &dev_attr_bat2.attr, 602 &dev_attr_disable.attr, 603 &dev_attr_dac.attr, 604 &dev_attr_gpio3.attr, 605 &dev_attr_gpio4.attr, 606 NULL 607 }; 608 609 static umode_t ad7877_attr_is_visible(struct kobject *kobj, 610 struct attribute *attr, int n) 611 { 612 umode_t mode = attr->mode; 613 614 if (attr == &dev_attr_aux3.attr) { 615 if (gpio3) 616 mode = 0; 617 } else if (attr == &dev_attr_gpio3.attr) { 618 if (!gpio3) 619 mode = 0; 620 } 621 622 return mode; 623 } 624 625 static const struct attribute_group ad7877_attr_group = { 626 .is_visible = ad7877_attr_is_visible, 627 .attrs = ad7877_attributes, 628 }; 629 630 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts) 631 { 632 struct spi_message *m; 633 int i; 634 635 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) | 636 AD7877_POL(ts->stopacq_polarity) | 637 AD7877_AVG(ts->averaging) | AD7877_PM(1) | 638 AD7877_TMR(ts->pen_down_acc_interval) | 639 AD7877_ACQ(ts->acquisition_time) | 640 AD7877_FCD(ts->first_conversion_delay); 641 642 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2); 643 644 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) | 645 AD7877_READADD(AD7877_REG_XPLUS-1) | 646 AD7877_MODE_SEQ1 | AD7877_DFR; 647 648 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1); 649 650 ts->cmd_dummy = 0; 651 652 m = &ts->msg; 653 654 spi_message_init(m); 655 656 m->context = ts; 657 658 ts->xfer[0].tx_buf = &ts->cmd_crtl1; 659 ts->xfer[0].len = 2; 660 ts->xfer[0].cs_change = 1; 661 662 spi_message_add_tail(&ts->xfer[0], m); 663 664 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */ 665 ts->xfer[1].len = 2; 666 ts->xfer[1].cs_change = 1; 667 668 spi_message_add_tail(&ts->xfer[1], m); 669 670 for (i = 0; i < AD7877_NR_SENSE; i++) { 671 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i]; 672 ts->xfer[i + 2].len = 2; 673 if (i < (AD7877_NR_SENSE - 1)) 674 ts->xfer[i + 2].cs_change = 1; 675 spi_message_add_tail(&ts->xfer[i + 2], m); 676 } 677 } 678 679 static int ad7877_probe(struct spi_device *spi) 680 { 681 struct ad7877 *ts; 682 struct input_dev *input_dev; 683 struct ad7877_platform_data *pdata = dev_get_platdata(&spi->dev); 684 int err; 685 u16 verify; 686 687 if (!spi->irq) { 688 dev_dbg(&spi->dev, "no IRQ?\n"); 689 return -ENODEV; 690 } 691 692 if (!pdata) { 693 dev_dbg(&spi->dev, "no platform data?\n"); 694 return -ENODEV; 695 } 696 697 /* don't exceed max specified SPI CLK frequency */ 698 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 699 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz); 700 return -EINVAL; 701 } 702 703 spi->bits_per_word = 16; 704 err = spi_setup(spi); 705 if (err) { 706 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n"); 707 return err; 708 } 709 710 ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL); 711 input_dev = input_allocate_device(); 712 if (!ts || !input_dev) { 713 err = -ENOMEM; 714 goto err_free_mem; 715 } 716 717 spi_set_drvdata(spi, ts); 718 ts->spi = spi; 719 ts->input = input_dev; 720 721 setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts); 722 mutex_init(&ts->mutex); 723 spin_lock_init(&ts->lock); 724 725 ts->model = pdata->model ? : 7877; 726 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 727 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 728 ts->pressure_max = pdata->pressure_max ? : ~0; 729 730 ts->stopacq_polarity = pdata->stopacq_polarity; 731 ts->first_conversion_delay = pdata->first_conversion_delay; 732 ts->acquisition_time = pdata->acquisition_time; 733 ts->averaging = pdata->averaging; 734 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 735 736 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 737 738 input_dev->name = "AD7877 Touchscreen"; 739 input_dev->phys = ts->phys; 740 input_dev->dev.parent = &spi->dev; 741 742 __set_bit(EV_KEY, input_dev->evbit); 743 __set_bit(BTN_TOUCH, input_dev->keybit); 744 __set_bit(EV_ABS, input_dev->evbit); 745 __set_bit(ABS_X, input_dev->absbit); 746 __set_bit(ABS_Y, input_dev->absbit); 747 __set_bit(ABS_PRESSURE, input_dev->absbit); 748 749 input_set_abs_params(input_dev, ABS_X, 750 pdata->x_min ? : 0, 751 pdata->x_max ? : MAX_12BIT, 752 0, 0); 753 input_set_abs_params(input_dev, ABS_Y, 754 pdata->y_min ? : 0, 755 pdata->y_max ? : MAX_12BIT, 756 0, 0); 757 input_set_abs_params(input_dev, ABS_PRESSURE, 758 pdata->pressure_min, pdata->pressure_max, 0, 0); 759 760 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE); 761 762 verify = ad7877_read(spi, AD7877_REG_SEQ1); 763 764 if (verify != AD7877_MM_SEQUENCE){ 765 dev_err(&spi->dev, "%s: Failed to probe %s\n", 766 dev_name(&spi->dev), input_dev->name); 767 err = -ENODEV; 768 goto err_free_mem; 769 } 770 771 if (gpio3) 772 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF); 773 774 ad7877_setup_ts_def_msg(spi, ts); 775 776 /* Request AD7877 /DAV GPIO interrupt */ 777 778 err = request_threaded_irq(spi->irq, NULL, ad7877_irq, 779 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 780 spi->dev.driver->name, ts); 781 if (err) { 782 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 783 goto err_free_mem; 784 } 785 786 err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group); 787 if (err) 788 goto err_free_irq; 789 790 err = input_register_device(input_dev); 791 if (err) 792 goto err_remove_attr_group; 793 794 return 0; 795 796 err_remove_attr_group: 797 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group); 798 err_free_irq: 799 free_irq(spi->irq, ts); 800 err_free_mem: 801 input_free_device(input_dev); 802 kfree(ts); 803 return err; 804 } 805 806 static int ad7877_remove(struct spi_device *spi) 807 { 808 struct ad7877 *ts = spi_get_drvdata(spi); 809 810 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group); 811 812 ad7877_disable(ts); 813 free_irq(ts->spi->irq, ts); 814 815 input_unregister_device(ts->input); 816 kfree(ts); 817 818 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 819 820 return 0; 821 } 822 823 static int __maybe_unused ad7877_suspend(struct device *dev) 824 { 825 struct ad7877 *ts = dev_get_drvdata(dev); 826 827 ad7877_disable(ts); 828 829 return 0; 830 } 831 832 static int __maybe_unused ad7877_resume(struct device *dev) 833 { 834 struct ad7877 *ts = dev_get_drvdata(dev); 835 836 ad7877_enable(ts); 837 838 return 0; 839 } 840 841 static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume); 842 843 static struct spi_driver ad7877_driver = { 844 .driver = { 845 .name = "ad7877", 846 .owner = THIS_MODULE, 847 .pm = &ad7877_pm, 848 }, 849 .probe = ad7877_probe, 850 .remove = ad7877_remove, 851 }; 852 853 module_spi_driver(ad7877_driver); 854 855 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 856 MODULE_DESCRIPTION("AD7877 touchscreen Driver"); 857 MODULE_LICENSE("GPL"); 858 MODULE_ALIAS("spi:ad7877"); 859