1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc. 4 * 5 * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver 6 * Based on: ads7846.c 7 * 8 * Bugs: Enter bugs at http://blackfin.uclinux.org/ 9 * 10 * History: 11 * Copyright (c) 2005 David Brownell 12 * Copyright (c) 2006 Nokia Corporation 13 * Various changes: Imre Deak <imre.deak@nokia.com> 14 * 15 * Using code from: 16 * - corgi_ts.c 17 * Copyright (C) 2004-2005 Richard Purdie 18 * - omap_ts.[hc], ads7846.h, ts_osk.c 19 * Copyright (C) 2002 MontaVista Software 20 * Copyright (C) 2004 Texas Instruments 21 * Copyright (C) 2005 Dirk Behme 22 */ 23 24 25 #include <linux/device.h> 26 #include <linux/delay.h> 27 #include <linux/input.h> 28 #include <linux/interrupt.h> 29 #include <linux/pm.h> 30 #include <linux/slab.h> 31 #include <linux/spi/spi.h> 32 #include <linux/spi/ad7877.h> 33 #include <linux/module.h> 34 #include <asm/irq.h> 35 36 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100) 37 38 #define MAX_SPI_FREQ_HZ 20000000 39 #define MAX_12BIT ((1<<12)-1) 40 41 #define AD7877_REG_ZEROS 0 42 #define AD7877_REG_CTRL1 1 43 #define AD7877_REG_CTRL2 2 44 #define AD7877_REG_ALERT 3 45 #define AD7877_REG_AUX1HIGH 4 46 #define AD7877_REG_AUX1LOW 5 47 #define AD7877_REG_BAT1HIGH 6 48 #define AD7877_REG_BAT1LOW 7 49 #define AD7877_REG_BAT2HIGH 8 50 #define AD7877_REG_BAT2LOW 9 51 #define AD7877_REG_TEMP1HIGH 10 52 #define AD7877_REG_TEMP1LOW 11 53 #define AD7877_REG_SEQ0 12 54 #define AD7877_REG_SEQ1 13 55 #define AD7877_REG_DAC 14 56 #define AD7877_REG_NONE1 15 57 #define AD7877_REG_EXTWRITE 15 58 #define AD7877_REG_XPLUS 16 59 #define AD7877_REG_YPLUS 17 60 #define AD7877_REG_Z2 18 61 #define AD7877_REG_aux1 19 62 #define AD7877_REG_aux2 20 63 #define AD7877_REG_aux3 21 64 #define AD7877_REG_bat1 22 65 #define AD7877_REG_bat2 23 66 #define AD7877_REG_temp1 24 67 #define AD7877_REG_temp2 25 68 #define AD7877_REG_Z1 26 69 #define AD7877_REG_GPIOCTRL1 27 70 #define AD7877_REG_GPIOCTRL2 28 71 #define AD7877_REG_GPIODATA 29 72 #define AD7877_REG_NONE2 30 73 #define AD7877_REG_NONE3 31 74 75 #define AD7877_SEQ_YPLUS_BIT (1<<11) 76 #define AD7877_SEQ_XPLUS_BIT (1<<10) 77 #define AD7877_SEQ_Z2_BIT (1<<9) 78 #define AD7877_SEQ_AUX1_BIT (1<<8) 79 #define AD7877_SEQ_AUX2_BIT (1<<7) 80 #define AD7877_SEQ_AUX3_BIT (1<<6) 81 #define AD7877_SEQ_BAT1_BIT (1<<5) 82 #define AD7877_SEQ_BAT2_BIT (1<<4) 83 #define AD7877_SEQ_TEMP1_BIT (1<<3) 84 #define AD7877_SEQ_TEMP2_BIT (1<<2) 85 #define AD7877_SEQ_Z1_BIT (1<<1) 86 87 enum { 88 AD7877_SEQ_YPOS = 0, 89 AD7877_SEQ_XPOS = 1, 90 AD7877_SEQ_Z2 = 2, 91 AD7877_SEQ_AUX1 = 3, 92 AD7877_SEQ_AUX2 = 4, 93 AD7877_SEQ_AUX3 = 5, 94 AD7877_SEQ_BAT1 = 6, 95 AD7877_SEQ_BAT2 = 7, 96 AD7877_SEQ_TEMP1 = 8, 97 AD7877_SEQ_TEMP2 = 9, 98 AD7877_SEQ_Z1 = 10, 99 AD7877_NR_SENSE = 11, 100 }; 101 102 /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */ 103 #define AD7877_DAC_CONF 0x1 104 105 /* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */ 106 #define AD7877_EXTW_GPIO_3_CONF 0x1C4 107 #define AD7877_EXTW_GPIO_DATA 0x200 108 109 /* Control REG 2 */ 110 #define AD7877_TMR(x) ((x & 0x3) << 0) 111 #define AD7877_REF(x) ((x & 0x1) << 2) 112 #define AD7877_POL(x) ((x & 0x1) << 3) 113 #define AD7877_FCD(x) ((x & 0x3) << 4) 114 #define AD7877_PM(x) ((x & 0x3) << 6) 115 #define AD7877_ACQ(x) ((x & 0x3) << 8) 116 #define AD7877_AVG(x) ((x & 0x3) << 10) 117 118 /* Control REG 1 */ 119 #define AD7877_SER (1 << 11) /* non-differential */ 120 #define AD7877_DFR (0 << 11) /* differential */ 121 122 #define AD7877_MODE_NOC (0) /* Do not convert */ 123 #define AD7877_MODE_SCC (1) /* Single channel conversion */ 124 #define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */ 125 #define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */ 126 127 #define AD7877_CHANADD(x) ((x&0xF)<<7) 128 #define AD7877_READADD(x) ((x)<<2) 129 #define AD7877_WRITEADD(x) ((x)<<12) 130 131 #define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \ 132 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \ 133 AD7877_READADD(AD7877_REG_ ## x)) 134 135 #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \ 136 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT) 137 138 /* 139 * Non-touchscreen sensors only use single-ended conversions. 140 */ 141 142 struct ser_req { 143 u16 reset; 144 u16 ref_on; 145 u16 command; 146 struct spi_message msg; 147 struct spi_transfer xfer[6]; 148 149 /* 150 * DMA (thus cache coherency maintenance) requires the 151 * transfer buffers to live in their own cache lines. 152 */ 153 u16 sample ____cacheline_aligned; 154 }; 155 156 struct ad7877 { 157 struct input_dev *input; 158 char phys[32]; 159 160 struct spi_device *spi; 161 u16 model; 162 u16 vref_delay_usecs; 163 u16 x_plate_ohms; 164 u16 pressure_max; 165 166 u16 cmd_crtl1; 167 u16 cmd_crtl2; 168 u16 cmd_dummy; 169 u16 dac; 170 171 u8 stopacq_polarity; 172 u8 first_conversion_delay; 173 u8 acquisition_time; 174 u8 averaging; 175 u8 pen_down_acc_interval; 176 177 struct spi_transfer xfer[AD7877_NR_SENSE + 2]; 178 struct spi_message msg; 179 180 struct mutex mutex; 181 bool disabled; /* P: mutex */ 182 bool gpio3; /* P: mutex */ 183 bool gpio4; /* P: mutex */ 184 185 spinlock_t lock; 186 struct timer_list timer; /* P: lock */ 187 188 /* 189 * DMA (thus cache coherency maintenance) requires the 190 * transfer buffers to live in their own cache lines. 191 */ 192 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned; 193 }; 194 195 static bool gpio3; 196 module_param(gpio3, bool, 0); 197 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3"); 198 199 static int ad7877_read(struct spi_device *spi, u16 reg) 200 { 201 struct ser_req *req; 202 int status, ret; 203 204 req = kzalloc(sizeof *req, GFP_KERNEL); 205 if (!req) 206 return -ENOMEM; 207 208 spi_message_init(&req->msg); 209 210 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) | 211 AD7877_READADD(reg)); 212 req->xfer[0].tx_buf = &req->command; 213 req->xfer[0].len = 2; 214 req->xfer[0].cs_change = 1; 215 216 req->xfer[1].rx_buf = &req->sample; 217 req->xfer[1].len = 2; 218 219 spi_message_add_tail(&req->xfer[0], &req->msg); 220 spi_message_add_tail(&req->xfer[1], &req->msg); 221 222 status = spi_sync(spi, &req->msg); 223 ret = status ? : req->sample; 224 225 kfree(req); 226 227 return ret; 228 } 229 230 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val) 231 { 232 struct ser_req *req; 233 int status; 234 235 req = kzalloc(sizeof *req, GFP_KERNEL); 236 if (!req) 237 return -ENOMEM; 238 239 spi_message_init(&req->msg); 240 241 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT)); 242 req->xfer[0].tx_buf = &req->command; 243 req->xfer[0].len = 2; 244 245 spi_message_add_tail(&req->xfer[0], &req->msg); 246 247 status = spi_sync(spi, &req->msg); 248 249 kfree(req); 250 251 return status; 252 } 253 254 static int ad7877_read_adc(struct spi_device *spi, unsigned command) 255 { 256 struct ad7877 *ts = spi_get_drvdata(spi); 257 struct ser_req *req; 258 int status; 259 int sample; 260 int i; 261 262 req = kzalloc(sizeof *req, GFP_KERNEL); 263 if (!req) 264 return -ENOMEM; 265 266 spi_message_init(&req->msg); 267 268 /* activate reference, so it has time to settle; */ 269 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) | 270 AD7877_POL(ts->stopacq_polarity) | 271 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) | 272 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0); 273 274 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC; 275 276 req->command = (u16) command; 277 278 req->xfer[0].tx_buf = &req->reset; 279 req->xfer[0].len = 2; 280 req->xfer[0].cs_change = 1; 281 282 req->xfer[1].tx_buf = &req->ref_on; 283 req->xfer[1].len = 2; 284 req->xfer[1].delay.value = ts->vref_delay_usecs; 285 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS; 286 req->xfer[1].cs_change = 1; 287 288 req->xfer[2].tx_buf = &req->command; 289 req->xfer[2].len = 2; 290 req->xfer[2].delay.value = ts->vref_delay_usecs; 291 req->xfer[2].delay.unit = SPI_DELAY_UNIT_USECS; 292 req->xfer[2].cs_change = 1; 293 294 req->xfer[3].rx_buf = &req->sample; 295 req->xfer[3].len = 2; 296 req->xfer[3].cs_change = 1; 297 298 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ 299 req->xfer[4].len = 2; 300 req->xfer[4].cs_change = 1; 301 302 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ 303 req->xfer[5].len = 2; 304 305 /* group all the transfers together, so we can't interfere with 306 * reading touchscreen state; disable penirq while sampling 307 */ 308 for (i = 0; i < 6; i++) 309 spi_message_add_tail(&req->xfer[i], &req->msg); 310 311 status = spi_sync(spi, &req->msg); 312 sample = req->sample; 313 314 kfree(req); 315 316 return status ? : sample; 317 } 318 319 static int ad7877_process_data(struct ad7877 *ts) 320 { 321 struct input_dev *input_dev = ts->input; 322 unsigned Rt; 323 u16 x, y, z1, z2; 324 325 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT; 326 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT; 327 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT; 328 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT; 329 330 /* 331 * The samples processed here are already preprocessed by the AD7877. 332 * The preprocessing function consists of an averaging filter. 333 * The combination of 'first conversion delay' and averaging provides a robust solution, 334 * discarding the spurious noise in the signal and keeping only the data of interest. 335 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h) 336 * Other user-programmable conversion controls include variable acquisition time, 337 * and first conversion delay. Up to 16 averages can be taken per conversion. 338 */ 339 340 if (likely(x && z1)) { 341 /* compute touch pressure resistance using equation #1 */ 342 Rt = (z2 - z1) * x * ts->x_plate_ohms; 343 Rt /= z1; 344 Rt = (Rt + 2047) >> 12; 345 346 /* 347 * Sample found inconsistent, pressure is beyond 348 * the maximum. Don't report it to user space. 349 */ 350 if (Rt > ts->pressure_max) 351 return -EINVAL; 352 353 if (!timer_pending(&ts->timer)) 354 input_report_key(input_dev, BTN_TOUCH, 1); 355 356 input_report_abs(input_dev, ABS_X, x); 357 input_report_abs(input_dev, ABS_Y, y); 358 input_report_abs(input_dev, ABS_PRESSURE, Rt); 359 input_sync(input_dev); 360 361 return 0; 362 } 363 364 return -EINVAL; 365 } 366 367 static inline void ad7877_ts_event_release(struct ad7877 *ts) 368 { 369 struct input_dev *input_dev = ts->input; 370 371 input_report_abs(input_dev, ABS_PRESSURE, 0); 372 input_report_key(input_dev, BTN_TOUCH, 0); 373 input_sync(input_dev); 374 } 375 376 static void ad7877_timer(struct timer_list *t) 377 { 378 struct ad7877 *ts = from_timer(ts, t, timer); 379 unsigned long flags; 380 381 spin_lock_irqsave(&ts->lock, flags); 382 ad7877_ts_event_release(ts); 383 spin_unlock_irqrestore(&ts->lock, flags); 384 } 385 386 static irqreturn_t ad7877_irq(int irq, void *handle) 387 { 388 struct ad7877 *ts = handle; 389 unsigned long flags; 390 int error; 391 392 error = spi_sync(ts->spi, &ts->msg); 393 if (error) { 394 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); 395 goto out; 396 } 397 398 spin_lock_irqsave(&ts->lock, flags); 399 error = ad7877_process_data(ts); 400 if (!error) 401 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT); 402 spin_unlock_irqrestore(&ts->lock, flags); 403 404 out: 405 return IRQ_HANDLED; 406 } 407 408 static void ad7877_disable(void *data) 409 { 410 struct ad7877 *ts = data; 411 412 mutex_lock(&ts->mutex); 413 414 if (!ts->disabled) { 415 ts->disabled = true; 416 disable_irq(ts->spi->irq); 417 418 if (del_timer_sync(&ts->timer)) 419 ad7877_ts_event_release(ts); 420 } 421 422 /* 423 * We know the chip's in lowpower mode since we always 424 * leave it that way after every request 425 */ 426 427 mutex_unlock(&ts->mutex); 428 } 429 430 static void ad7877_enable(struct ad7877 *ts) 431 { 432 mutex_lock(&ts->mutex); 433 434 if (ts->disabled) { 435 ts->disabled = false; 436 enable_irq(ts->spi->irq); 437 } 438 439 mutex_unlock(&ts->mutex); 440 } 441 442 #define SHOW(name) static ssize_t \ 443 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 444 { \ 445 struct ad7877 *ts = dev_get_drvdata(dev); \ 446 ssize_t v = ad7877_read_adc(ts->spi, \ 447 AD7877_READ_CHAN(name)); \ 448 if (v < 0) \ 449 return v; \ 450 return sprintf(buf, "%u\n", (unsigned) v); \ 451 } \ 452 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 453 454 SHOW(aux1) 455 SHOW(aux2) 456 SHOW(aux3) 457 SHOW(bat1) 458 SHOW(bat2) 459 SHOW(temp1) 460 SHOW(temp2) 461 462 static ssize_t ad7877_disable_show(struct device *dev, 463 struct device_attribute *attr, char *buf) 464 { 465 struct ad7877 *ts = dev_get_drvdata(dev); 466 467 return sprintf(buf, "%u\n", ts->disabled); 468 } 469 470 static ssize_t ad7877_disable_store(struct device *dev, 471 struct device_attribute *attr, 472 const char *buf, size_t count) 473 { 474 struct ad7877 *ts = dev_get_drvdata(dev); 475 unsigned int val; 476 int error; 477 478 error = kstrtouint(buf, 10, &val); 479 if (error) 480 return error; 481 482 if (val) 483 ad7877_disable(ts); 484 else 485 ad7877_enable(ts); 486 487 return count; 488 } 489 490 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store); 491 492 static ssize_t ad7877_dac_show(struct device *dev, 493 struct device_attribute *attr, char *buf) 494 { 495 struct ad7877 *ts = dev_get_drvdata(dev); 496 497 return sprintf(buf, "%u\n", ts->dac); 498 } 499 500 static ssize_t ad7877_dac_store(struct device *dev, 501 struct device_attribute *attr, 502 const char *buf, size_t count) 503 { 504 struct ad7877 *ts = dev_get_drvdata(dev); 505 unsigned int val; 506 int error; 507 508 error = kstrtouint(buf, 10, &val); 509 if (error) 510 return error; 511 512 mutex_lock(&ts->mutex); 513 ts->dac = val & 0xFF; 514 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF); 515 mutex_unlock(&ts->mutex); 516 517 return count; 518 } 519 520 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store); 521 522 static ssize_t ad7877_gpio3_show(struct device *dev, 523 struct device_attribute *attr, char *buf) 524 { 525 struct ad7877 *ts = dev_get_drvdata(dev); 526 527 return sprintf(buf, "%u\n", ts->gpio3); 528 } 529 530 static ssize_t ad7877_gpio3_store(struct device *dev, 531 struct device_attribute *attr, 532 const char *buf, size_t count) 533 { 534 struct ad7877 *ts = dev_get_drvdata(dev); 535 unsigned int val; 536 int error; 537 538 error = kstrtouint(buf, 10, &val); 539 if (error) 540 return error; 541 542 mutex_lock(&ts->mutex); 543 ts->gpio3 = !!val; 544 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 545 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 546 mutex_unlock(&ts->mutex); 547 548 return count; 549 } 550 551 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store); 552 553 static ssize_t ad7877_gpio4_show(struct device *dev, 554 struct device_attribute *attr, char *buf) 555 { 556 struct ad7877 *ts = dev_get_drvdata(dev); 557 558 return sprintf(buf, "%u\n", ts->gpio4); 559 } 560 561 static ssize_t ad7877_gpio4_store(struct device *dev, 562 struct device_attribute *attr, 563 const char *buf, size_t count) 564 { 565 struct ad7877 *ts = dev_get_drvdata(dev); 566 unsigned int val; 567 int error; 568 569 error = kstrtouint(buf, 10, &val); 570 if (error) 571 return error; 572 573 mutex_lock(&ts->mutex); 574 ts->gpio4 = !!val; 575 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA | 576 (ts->gpio4 << 4) | (ts->gpio3 << 5)); 577 mutex_unlock(&ts->mutex); 578 579 return count; 580 } 581 582 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store); 583 584 static struct attribute *ad7877_attributes[] = { 585 &dev_attr_temp1.attr, 586 &dev_attr_temp2.attr, 587 &dev_attr_aux1.attr, 588 &dev_attr_aux2.attr, 589 &dev_attr_aux3.attr, 590 &dev_attr_bat1.attr, 591 &dev_attr_bat2.attr, 592 &dev_attr_disable.attr, 593 &dev_attr_dac.attr, 594 &dev_attr_gpio3.attr, 595 &dev_attr_gpio4.attr, 596 NULL 597 }; 598 599 static umode_t ad7877_attr_is_visible(struct kobject *kobj, 600 struct attribute *attr, int n) 601 { 602 umode_t mode = attr->mode; 603 604 if (attr == &dev_attr_aux3.attr) { 605 if (gpio3) 606 mode = 0; 607 } else if (attr == &dev_attr_gpio3.attr) { 608 if (!gpio3) 609 mode = 0; 610 } 611 612 return mode; 613 } 614 615 static const struct attribute_group ad7877_attr_group = { 616 .is_visible = ad7877_attr_is_visible, 617 .attrs = ad7877_attributes, 618 }; 619 620 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts) 621 { 622 struct spi_message *m; 623 int i; 624 625 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) | 626 AD7877_POL(ts->stopacq_polarity) | 627 AD7877_AVG(ts->averaging) | AD7877_PM(1) | 628 AD7877_TMR(ts->pen_down_acc_interval) | 629 AD7877_ACQ(ts->acquisition_time) | 630 AD7877_FCD(ts->first_conversion_delay); 631 632 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2); 633 634 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) | 635 AD7877_READADD(AD7877_REG_XPLUS-1) | 636 AD7877_MODE_SEQ1 | AD7877_DFR; 637 638 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1); 639 640 ts->cmd_dummy = 0; 641 642 m = &ts->msg; 643 644 spi_message_init(m); 645 646 m->context = ts; 647 648 ts->xfer[0].tx_buf = &ts->cmd_crtl1; 649 ts->xfer[0].len = 2; 650 ts->xfer[0].cs_change = 1; 651 652 spi_message_add_tail(&ts->xfer[0], m); 653 654 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */ 655 ts->xfer[1].len = 2; 656 ts->xfer[1].cs_change = 1; 657 658 spi_message_add_tail(&ts->xfer[1], m); 659 660 for (i = 0; i < AD7877_NR_SENSE; i++) { 661 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i]; 662 ts->xfer[i + 2].len = 2; 663 if (i < (AD7877_NR_SENSE - 1)) 664 ts->xfer[i + 2].cs_change = 1; 665 spi_message_add_tail(&ts->xfer[i + 2], m); 666 } 667 } 668 669 static int ad7877_probe(struct spi_device *spi) 670 { 671 struct ad7877 *ts; 672 struct input_dev *input_dev; 673 struct ad7877_platform_data *pdata = dev_get_platdata(&spi->dev); 674 int err; 675 u16 verify; 676 677 if (!spi->irq) { 678 dev_dbg(&spi->dev, "no IRQ?\n"); 679 return -ENODEV; 680 } 681 682 if (!pdata) { 683 dev_dbg(&spi->dev, "no platform data?\n"); 684 return -ENODEV; 685 } 686 687 /* don't exceed max specified SPI CLK frequency */ 688 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) { 689 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz); 690 return -EINVAL; 691 } 692 693 spi->bits_per_word = 16; 694 err = spi_setup(spi); 695 if (err) { 696 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n"); 697 return err; 698 } 699 700 ts = devm_kzalloc(&spi->dev, sizeof(struct ad7877), GFP_KERNEL); 701 if (!ts) 702 return -ENOMEM; 703 704 input_dev = devm_input_allocate_device(&spi->dev); 705 if (!input_dev) 706 return -ENOMEM; 707 708 err = devm_add_action_or_reset(&spi->dev, ad7877_disable, ts); 709 if (err) 710 return err; 711 712 spi_set_drvdata(spi, ts); 713 ts->spi = spi; 714 ts->input = input_dev; 715 716 timer_setup(&ts->timer, ad7877_timer, 0); 717 mutex_init(&ts->mutex); 718 spin_lock_init(&ts->lock); 719 720 ts->model = pdata->model ? : 7877; 721 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 722 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 723 ts->pressure_max = pdata->pressure_max ? : ~0; 724 725 ts->stopacq_polarity = pdata->stopacq_polarity; 726 ts->first_conversion_delay = pdata->first_conversion_delay; 727 ts->acquisition_time = pdata->acquisition_time; 728 ts->averaging = pdata->averaging; 729 ts->pen_down_acc_interval = pdata->pen_down_acc_interval; 730 731 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); 732 733 input_dev->name = "AD7877 Touchscreen"; 734 input_dev->phys = ts->phys; 735 input_dev->dev.parent = &spi->dev; 736 737 __set_bit(EV_KEY, input_dev->evbit); 738 __set_bit(BTN_TOUCH, input_dev->keybit); 739 __set_bit(EV_ABS, input_dev->evbit); 740 __set_bit(ABS_X, input_dev->absbit); 741 __set_bit(ABS_Y, input_dev->absbit); 742 __set_bit(ABS_PRESSURE, input_dev->absbit); 743 744 input_set_abs_params(input_dev, ABS_X, 745 pdata->x_min ? : 0, 746 pdata->x_max ? : MAX_12BIT, 747 0, 0); 748 input_set_abs_params(input_dev, ABS_Y, 749 pdata->y_min ? : 0, 750 pdata->y_max ? : MAX_12BIT, 751 0, 0); 752 input_set_abs_params(input_dev, ABS_PRESSURE, 753 pdata->pressure_min, pdata->pressure_max, 0, 0); 754 755 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE); 756 757 verify = ad7877_read(spi, AD7877_REG_SEQ1); 758 759 if (verify != AD7877_MM_SEQUENCE) { 760 dev_err(&spi->dev, "%s: Failed to probe %s\n", 761 dev_name(&spi->dev), input_dev->name); 762 return -ENODEV; 763 } 764 765 if (gpio3) 766 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF); 767 768 ad7877_setup_ts_def_msg(spi, ts); 769 770 /* Request AD7877 /DAV GPIO interrupt */ 771 772 err = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, ad7877_irq, 773 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 774 spi->dev.driver->name, ts); 775 if (err) { 776 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 777 return err; 778 } 779 780 err = devm_device_add_group(&spi->dev, &ad7877_attr_group); 781 if (err) 782 return err; 783 784 err = input_register_device(input_dev); 785 if (err) 786 return err; 787 788 return 0; 789 } 790 791 static int ad7877_suspend(struct device *dev) 792 { 793 struct ad7877 *ts = dev_get_drvdata(dev); 794 795 ad7877_disable(ts); 796 797 return 0; 798 } 799 800 static int ad7877_resume(struct device *dev) 801 { 802 struct ad7877 *ts = dev_get_drvdata(dev); 803 804 ad7877_enable(ts); 805 806 return 0; 807 } 808 809 static DEFINE_SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume); 810 811 static struct spi_driver ad7877_driver = { 812 .driver = { 813 .name = "ad7877", 814 .pm = pm_sleep_ptr(&ad7877_pm), 815 }, 816 .probe = ad7877_probe, 817 }; 818 819 module_spi_driver(ad7877_driver); 820 821 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 822 MODULE_DESCRIPTION("AD7877 touchscreen Driver"); 823 MODULE_LICENSE("GPL"); 824 MODULE_ALIAS("spi:ad7877"); 825