1 /* 2 * ADS7846 based touchscreen and sensor driver 3 * 4 * Copyright (c) 2005 David Brownell 5 * Copyright (c) 2006 Nokia Corporation 6 * Various changes: Imre Deak <imre.deak@nokia.com> 7 * 8 * Using code from: 9 * - corgi_ts.c 10 * Copyright (C) 2004-2005 Richard Purdie 11 * - omap_ts.[hc], ads7846.h, ts_osk.c 12 * Copyright (C) 2002 MontaVista Software 13 * Copyright (C) 2004 Texas Instruments 14 * Copyright (C) 2005 Dirk Behme 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License version 2 as 18 * published by the Free Software Foundation. 19 */ 20 #include <linux/device.h> 21 #include <linux/init.h> 22 #include <linux/delay.h> 23 #include <linux/input.h> 24 #include <linux/interrupt.h> 25 #include <linux/slab.h> 26 #include <linux/spi/spi.h> 27 #include <linux/spi/ads7846.h> 28 #include <asm/irq.h> 29 30 #ifdef CONFIG_ARM 31 #include <asm/mach-types.h> 32 #ifdef CONFIG_ARCH_OMAP 33 #include <asm/arch/gpio.h> 34 #endif 35 #endif 36 37 38 /* 39 * This code has been heavily tested on a Nokia 770, and lightly 40 * tested on other ads7846 devices (OSK/Mistral, Lubbock). 41 * Support for ads7843 and ads7845 has only been stubbed in. 42 * 43 * IRQ handling needs a workaround because of a shortcoming in handling 44 * edge triggered IRQs on some platforms like the OMAP1/2. These 45 * platforms don't handle the ARM lazy IRQ disabling properly, thus we 46 * have to maintain our own SW IRQ disabled status. This should be 47 * removed as soon as the affected platform's IRQ handling is fixed. 48 * 49 * app note sbaa036 talks in more detail about accurate sampling... 50 * that ought to help in situations like LCDs inducing noise (which 51 * can also be helped by using synch signals) and more generally. 52 * This driver tries to utilize the measures described in the app 53 * note. The strength of filtering can be set in the board-* specific 54 * files. 55 */ 56 57 #define TS_POLL_PERIOD msecs_to_jiffies(10) 58 59 /* this driver doesn't aim at the peak continuous sample rate */ 60 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) 61 62 struct ts_event { 63 /* For portability, we can't read 12 bit values using SPI (which 64 * would make the controller deliver them as native byteorder u16 65 * with msbs zeroed). Instead, we read them as two 8-bit values, 66 * *** WHICH NEED BYTESWAPPING *** and range adjustment. 67 */ 68 u16 x; 69 u16 y; 70 u16 z1, z2; 71 int ignore; 72 }; 73 74 struct ads7846 { 75 struct input_dev *input; 76 char phys[32]; 77 78 struct spi_device *spi; 79 struct attribute_group *attr_group; 80 u16 model; 81 u16 vref_delay_usecs; 82 u16 x_plate_ohms; 83 u16 pressure_max; 84 85 u8 read_x, read_y, read_z1, read_z2, pwrdown; 86 u16 dummy; /* for the pwrdown read */ 87 struct ts_event tc; 88 89 struct spi_transfer xfer[10]; 90 struct spi_message msg[5]; 91 struct spi_message *last_msg; 92 int msg_idx; 93 int read_cnt; 94 int read_rep; 95 int last_read; 96 97 u16 debounce_max; 98 u16 debounce_tol; 99 u16 debounce_rep; 100 101 spinlock_t lock; 102 struct timer_list timer; /* P: lock */ 103 unsigned pendown:1; /* P: lock */ 104 unsigned pending:1; /* P: lock */ 105 // FIXME remove "irq_disabled" 106 unsigned irq_disabled:1; /* P: lock */ 107 unsigned disabled:1; 108 109 int (*filter)(void *data, int data_idx, int *val); 110 void *filter_data; 111 void (*filter_cleanup)(void *data); 112 int (*get_pendown_state)(void); 113 }; 114 115 /* leave chip selected when we're done, for quicker re-select? */ 116 #if 0 117 #define CS_CHANGE(xfer) ((xfer).cs_change = 1) 118 #else 119 #define CS_CHANGE(xfer) ((xfer).cs_change = 0) 120 #endif 121 122 /*--------------------------------------------------------------------------*/ 123 124 /* The ADS7846 has touchscreen and other sensors. 125 * Earlier ads784x chips are somewhat compatible. 126 */ 127 #define ADS_START (1 << 7) 128 #define ADS_A2A1A0_d_y (1 << 4) /* differential */ 129 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */ 130 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */ 131 #define ADS_A2A1A0_d_x (5 << 4) /* differential */ 132 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */ 133 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */ 134 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */ 135 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */ 136 #define ADS_8_BIT (1 << 3) 137 #define ADS_12_BIT (0 << 3) 138 #define ADS_SER (1 << 2) /* non-differential */ 139 #define ADS_DFR (0 << 2) /* differential */ 140 #define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */ 141 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */ 142 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */ 143 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */ 144 145 #define MAX_12BIT ((1<<12)-1) 146 147 /* leave ADC powered up (disables penirq) between differential samples */ 148 #define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \ 149 | ADS_12_BIT | ADS_DFR) 150 151 #define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON) 152 #define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON) 153 #define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON) 154 155 #define READ_X (READ_12BIT_DFR(x) | ADS_PD10_ADC_ON) 156 #define PWRDOWN (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) /* LAST */ 157 158 /* single-ended samples need to first power up reference voltage; 159 * we leave both ADC and VREF powered 160 */ 161 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ 162 | ADS_12_BIT | ADS_SER) 163 164 #define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON) 165 #define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) 166 167 /*--------------------------------------------------------------------------*/ 168 169 /* 170 * Non-touchscreen sensors only use single-ended conversions. 171 */ 172 173 struct ser_req { 174 u8 ref_on; 175 u8 command; 176 u8 ref_off; 177 u16 scratch; 178 __be16 sample; 179 struct spi_message msg; 180 struct spi_transfer xfer[6]; 181 }; 182 183 static void ads7846_enable(struct ads7846 *ts); 184 static void ads7846_disable(struct ads7846 *ts); 185 186 static int device_suspended(struct device *dev) 187 { 188 struct ads7846 *ts = dev_get_drvdata(dev); 189 return dev->power.power_state.event != PM_EVENT_ON || ts->disabled; 190 } 191 192 static int ads7846_read12_ser(struct device *dev, unsigned command) 193 { 194 struct spi_device *spi = to_spi_device(dev); 195 struct ads7846 *ts = dev_get_drvdata(dev); 196 struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL); 197 int status; 198 int sample; 199 int i; 200 201 if (!req) 202 return -ENOMEM; 203 204 spi_message_init(&req->msg); 205 206 /* activate reference, so it has time to settle; */ 207 req->ref_on = REF_ON; 208 req->xfer[0].tx_buf = &req->ref_on; 209 req->xfer[0].len = 1; 210 req->xfer[1].rx_buf = &req->scratch; 211 req->xfer[1].len = 2; 212 213 /* 214 * for external VREF, 0 usec (and assume it's always on); 215 * for 1uF, use 800 usec; 216 * no cap, 100 usec. 217 */ 218 req->xfer[1].delay_usecs = ts->vref_delay_usecs; 219 220 /* take sample */ 221 req->command = (u8) command; 222 req->xfer[2].tx_buf = &req->command; 223 req->xfer[2].len = 1; 224 req->xfer[3].rx_buf = &req->sample; 225 req->xfer[3].len = 2; 226 227 /* REVISIT: take a few more samples, and compare ... */ 228 229 /* turn off reference */ 230 req->ref_off = REF_OFF; 231 req->xfer[4].tx_buf = &req->ref_off; 232 req->xfer[4].len = 1; 233 req->xfer[5].rx_buf = &req->scratch; 234 req->xfer[5].len = 2; 235 236 CS_CHANGE(req->xfer[5]); 237 238 /* group all the transfers together, so we can't interfere with 239 * reading touchscreen state; disable penirq while sampling 240 */ 241 for (i = 0; i < 6; i++) 242 spi_message_add_tail(&req->xfer[i], &req->msg); 243 244 ts->irq_disabled = 1; 245 disable_irq(spi->irq); 246 status = spi_sync(spi, &req->msg); 247 ts->irq_disabled = 0; 248 enable_irq(spi->irq); 249 250 if (req->msg.status) 251 status = req->msg.status; 252 253 /* on-wire is a must-ignore bit, a BE12 value, then padding */ 254 sample = be16_to_cpu(req->sample); 255 sample = sample >> 3; 256 sample &= 0x0fff; 257 258 kfree(req); 259 return status ? status : sample; 260 } 261 262 #define SHOW(name) static ssize_t \ 263 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ 264 { \ 265 ssize_t v = ads7846_read12_ser(dev, \ 266 READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \ 267 if (v < 0) \ 268 return v; \ 269 return sprintf(buf, "%u\n", (unsigned) v); \ 270 } \ 271 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL); 272 273 SHOW(temp0) 274 SHOW(temp1) 275 SHOW(vaux) 276 SHOW(vbatt) 277 278 static int is_pen_down(struct device *dev) 279 { 280 struct ads7846 *ts = dev_get_drvdata(dev); 281 282 return ts->pendown; 283 } 284 285 static ssize_t ads7846_pen_down_show(struct device *dev, 286 struct device_attribute *attr, char *buf) 287 { 288 return sprintf(buf, "%u\n", is_pen_down(dev)); 289 } 290 291 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL); 292 293 static ssize_t ads7846_disable_show(struct device *dev, 294 struct device_attribute *attr, char *buf) 295 { 296 struct ads7846 *ts = dev_get_drvdata(dev); 297 298 return sprintf(buf, "%u\n", ts->disabled); 299 } 300 301 static ssize_t ads7846_disable_store(struct device *dev, 302 struct device_attribute *attr, 303 const char *buf, size_t count) 304 { 305 struct ads7846 *ts = dev_get_drvdata(dev); 306 char *endp; 307 int i; 308 309 i = simple_strtoul(buf, &endp, 10); 310 spin_lock_irq(&ts->lock); 311 312 if (i) 313 ads7846_disable(ts); 314 else 315 ads7846_enable(ts); 316 317 spin_unlock_irq(&ts->lock); 318 319 return count; 320 } 321 322 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); 323 324 static struct attribute *ads7846_attributes[] = { 325 &dev_attr_temp0.attr, 326 &dev_attr_temp1.attr, 327 &dev_attr_vbatt.attr, 328 &dev_attr_vaux.attr, 329 &dev_attr_pen_down.attr, 330 &dev_attr_disable.attr, 331 NULL, 332 }; 333 334 static struct attribute_group ads7846_attr_group = { 335 .attrs = ads7846_attributes, 336 }; 337 338 /* 339 * ads7843/7845 don't have temperature sensors, and 340 * use the other sensors a bit differently too 341 */ 342 343 static struct attribute *ads7843_attributes[] = { 344 &dev_attr_vbatt.attr, 345 &dev_attr_vaux.attr, 346 &dev_attr_pen_down.attr, 347 &dev_attr_disable.attr, 348 NULL, 349 }; 350 351 static struct attribute_group ads7843_attr_group = { 352 .attrs = ads7843_attributes, 353 }; 354 355 static struct attribute *ads7845_attributes[] = { 356 &dev_attr_vaux.attr, 357 &dev_attr_pen_down.attr, 358 &dev_attr_disable.attr, 359 NULL, 360 }; 361 362 static struct attribute_group ads7845_attr_group = { 363 .attrs = ads7845_attributes, 364 }; 365 366 /*--------------------------------------------------------------------------*/ 367 368 /* 369 * PENIRQ only kicks the timer. The timer only reissues the SPI transfer, 370 * to retrieve touchscreen status. 371 * 372 * The SPI transfer completion callback does the real work. It reports 373 * touchscreen events and reactivates the timer (or IRQ) as appropriate. 374 */ 375 376 static void ads7846_rx(void *ads) 377 { 378 struct ads7846 *ts = ads; 379 struct input_dev *input_dev = ts->input; 380 unsigned Rt; 381 unsigned sync = 0; 382 u16 x, y, z1, z2; 383 unsigned long flags; 384 385 /* ads7846_rx_val() did in-place conversion (including byteswap) from 386 * on-the-wire format as part of debouncing to get stable readings. 387 */ 388 x = ts->tc.x; 389 y = ts->tc.y; 390 z1 = ts->tc.z1; 391 z2 = ts->tc.z2; 392 393 /* range filtering */ 394 if (x == MAX_12BIT) 395 x = 0; 396 397 if (likely(x && z1 && !device_suspended(&ts->spi->dev))) { 398 /* compute touch pressure resistance using equation #2 */ 399 Rt = z2; 400 Rt -= z1; 401 Rt *= x; 402 Rt *= ts->x_plate_ohms; 403 Rt /= z1; 404 Rt = (Rt + 2047) >> 12; 405 } else 406 Rt = 0; 407 408 /* Sample found inconsistent by debouncing or pressure is beyond 409 * the maximum. Don't report it to user space, repeat at least 410 * once more the measurement */ 411 if (ts->tc.ignore || Rt > ts->pressure_max) { 412 mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD); 413 return; 414 } 415 416 /* NOTE: "pendown" is inferred from pressure; we don't rely on 417 * being able to check nPENIRQ status, or "friendly" trigger modes 418 * (both-edges is much better than just-falling or low-level). 419 * 420 * REVISIT: some boards may require reading nPENIRQ; it's 421 * needed on 7843. and 7845 reads pressure differently... 422 * 423 * REVISIT: the touchscreen might not be connected; this code 424 * won't notice that, even if nPENIRQ never fires ... 425 */ 426 if (!ts->pendown && Rt != 0) { 427 input_report_key(input_dev, BTN_TOUCH, 1); 428 sync = 1; 429 } else if (ts->pendown && Rt == 0) { 430 input_report_key(input_dev, BTN_TOUCH, 0); 431 sync = 1; 432 } 433 434 if (Rt) { 435 input_report_abs(input_dev, ABS_X, x); 436 input_report_abs(input_dev, ABS_Y, y); 437 sync = 1; 438 } 439 440 if (sync) { 441 input_report_abs(input_dev, ABS_PRESSURE, Rt); 442 input_sync(input_dev); 443 } 444 445 #ifdef VERBOSE 446 if (Rt || ts->pendown) 447 pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id, 448 x, y, Rt, Rt ? "" : " UP"); 449 #endif 450 451 spin_lock_irqsave(&ts->lock, flags); 452 453 ts->pendown = (Rt != 0); 454 mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD); 455 456 spin_unlock_irqrestore(&ts->lock, flags); 457 } 458 459 static int ads7846_debounce(void *ads, int data_idx, int *val) 460 { 461 struct ads7846 *ts = ads; 462 463 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) { 464 /* Start over collecting consistent readings. */ 465 ts->read_rep = 0; 466 /* Repeat it, if this was the first read or the read 467 * wasn't consistent enough. */ 468 if (ts->read_cnt < ts->debounce_max) { 469 ts->last_read = *val; 470 ts->read_cnt++; 471 return ADS7846_FILTER_REPEAT; 472 } else { 473 /* Maximum number of debouncing reached and still 474 * not enough number of consistent readings. Abort 475 * the whole sample, repeat it in the next sampling 476 * period. 477 */ 478 ts->read_cnt = 0; 479 return ADS7846_FILTER_IGNORE; 480 } 481 } else { 482 if (++ts->read_rep > ts->debounce_rep) { 483 /* Got a good reading for this coordinate, 484 * go for the next one. */ 485 ts->read_cnt = 0; 486 ts->read_rep = 0; 487 return ADS7846_FILTER_OK; 488 } else { 489 /* Read more values that are consistent. */ 490 ts->read_cnt++; 491 return ADS7846_FILTER_REPEAT; 492 } 493 } 494 } 495 496 static int ads7846_no_filter(void *ads, int data_idx, int *val) 497 { 498 return ADS7846_FILTER_OK; 499 } 500 501 static void ads7846_rx_val(void *ads) 502 { 503 struct ads7846 *ts = ads; 504 struct spi_message *m; 505 struct spi_transfer *t; 506 u16 *rx_val; 507 int val; 508 int action; 509 int status; 510 511 m = &ts->msg[ts->msg_idx]; 512 t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list); 513 rx_val = t->rx_buf; 514 515 /* adjust: on-wire is a must-ignore bit, a BE12 value, then padding; 516 * built from two 8 bit values written msb-first. 517 */ 518 val = be16_to_cpu(*rx_val) >> 3; 519 520 action = ts->filter(ts->filter_data, ts->msg_idx, &val); 521 switch (action) { 522 case ADS7846_FILTER_REPEAT: 523 break; 524 case ADS7846_FILTER_IGNORE: 525 ts->tc.ignore = 1; 526 /* Last message will contain ads7846_rx() as the 527 * completion function. 528 */ 529 m = ts->last_msg; 530 break; 531 case ADS7846_FILTER_OK: 532 *rx_val = val; 533 ts->tc.ignore = 0; 534 m = &ts->msg[++ts->msg_idx]; 535 break; 536 default: 537 BUG(); 538 } 539 status = spi_async(ts->spi, m); 540 if (status) 541 dev_err(&ts->spi->dev, "spi_async --> %d\n", 542 status); 543 } 544 545 static void ads7846_timer(unsigned long handle) 546 { 547 struct ads7846 *ts = (void *)handle; 548 int status = 0; 549 550 spin_lock_irq(&ts->lock); 551 552 if (unlikely(ts->msg_idx && !ts->pendown)) { 553 /* measurement cycle ended */ 554 if (!device_suspended(&ts->spi->dev)) { 555 ts->irq_disabled = 0; 556 enable_irq(ts->spi->irq); 557 } 558 ts->pending = 0; 559 ts->msg_idx = 0; 560 } else { 561 /* pen is still down, continue with the measurement */ 562 ts->msg_idx = 0; 563 status = spi_async(ts->spi, &ts->msg[0]); 564 if (status) 565 dev_err(&ts->spi->dev, "spi_async --> %d\n", status); 566 } 567 568 spin_unlock_irq(&ts->lock); 569 } 570 571 static irqreturn_t ads7846_irq(int irq, void *handle) 572 { 573 struct ads7846 *ts = handle; 574 unsigned long flags; 575 576 spin_lock_irqsave(&ts->lock, flags); 577 if (likely(ts->get_pendown_state())) { 578 if (!ts->irq_disabled) { 579 /* The ARM do_simple_IRQ() dispatcher doesn't act 580 * like the other dispatchers: it will report IRQs 581 * even after they've been disabled. We work around 582 * that here. (The "generic irq" framework may help...) 583 */ 584 ts->irq_disabled = 1; 585 disable_irq(ts->spi->irq); 586 ts->pending = 1; 587 mod_timer(&ts->timer, jiffies); 588 } 589 } 590 spin_unlock_irqrestore(&ts->lock, flags); 591 592 return IRQ_HANDLED; 593 } 594 595 /*--------------------------------------------------------------------------*/ 596 597 /* Must be called with ts->lock held */ 598 static void ads7846_disable(struct ads7846 *ts) 599 { 600 if (ts->disabled) 601 return; 602 603 ts->disabled = 1; 604 605 /* are we waiting for IRQ, or polling? */ 606 if (!ts->pending) { 607 ts->irq_disabled = 1; 608 disable_irq(ts->spi->irq); 609 } else { 610 /* the timer will run at least once more, and 611 * leave everything in a clean state, IRQ disabled 612 */ 613 while (ts->pending) { 614 spin_unlock_irq(&ts->lock); 615 msleep(1); 616 spin_lock_irq(&ts->lock); 617 } 618 } 619 620 /* we know the chip's in lowpower mode since we always 621 * leave it that way after every request 622 */ 623 624 } 625 626 /* Must be called with ts->lock held */ 627 static void ads7846_enable(struct ads7846 *ts) 628 { 629 if (!ts->disabled) 630 return; 631 632 ts->disabled = 0; 633 ts->irq_disabled = 0; 634 enable_irq(ts->spi->irq); 635 } 636 637 static int ads7846_suspend(struct spi_device *spi, pm_message_t message) 638 { 639 struct ads7846 *ts = dev_get_drvdata(&spi->dev); 640 641 spin_lock_irq(&ts->lock); 642 643 spi->dev.power.power_state = message; 644 ads7846_disable(ts); 645 646 spin_unlock_irq(&ts->lock); 647 648 return 0; 649 650 } 651 652 static int ads7846_resume(struct spi_device *spi) 653 { 654 struct ads7846 *ts = dev_get_drvdata(&spi->dev); 655 656 spin_lock_irq(&ts->lock); 657 658 spi->dev.power.power_state = PMSG_ON; 659 ads7846_enable(ts); 660 661 spin_unlock_irq(&ts->lock); 662 663 return 0; 664 } 665 666 static int __devinit ads7846_probe(struct spi_device *spi) 667 { 668 struct ads7846 *ts; 669 struct input_dev *input_dev; 670 struct ads7846_platform_data *pdata = spi->dev.platform_data; 671 struct spi_message *m; 672 struct spi_transfer *x; 673 int err; 674 675 if (!spi->irq) { 676 dev_dbg(&spi->dev, "no IRQ?\n"); 677 return -ENODEV; 678 } 679 680 if (!pdata) { 681 dev_dbg(&spi->dev, "no platform data?\n"); 682 return -ENODEV; 683 } 684 685 /* don't exceed max specified sample rate */ 686 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { 687 dev_dbg(&spi->dev, "f(sample) %d KHz?\n", 688 (spi->max_speed_hz/SAMPLE_BITS)/1000); 689 return -EINVAL; 690 } 691 692 /* REVISIT when the irq can be triggered active-low, or if for some 693 * reason the touchscreen isn't hooked up, we don't need to access 694 * the pendown state. 695 */ 696 if (pdata->get_pendown_state == NULL) { 697 dev_dbg(&spi->dev, "no get_pendown_state function?\n"); 698 return -EINVAL; 699 } 700 701 /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except 702 * that even if the hardware can do that, the SPI controller driver 703 * may not. So we stick to very-portable 8 bit words, both RX and TX. 704 */ 705 spi->bits_per_word = 8; 706 707 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); 708 input_dev = input_allocate_device(); 709 if (!ts || !input_dev) { 710 err = -ENOMEM; 711 goto err_free_mem; 712 } 713 714 dev_set_drvdata(&spi->dev, ts); 715 spi->dev.power.power_state = PMSG_ON; 716 717 ts->spi = spi; 718 ts->input = input_dev; 719 720 init_timer(&ts->timer); 721 ts->timer.data = (unsigned long) ts; 722 ts->timer.function = ads7846_timer; 723 724 spin_lock_init(&ts->lock); 725 726 ts->model = pdata->model ? : 7846; 727 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; 728 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; 729 ts->pressure_max = pdata->pressure_max ? : ~0; 730 731 if (pdata->filter != NULL) { 732 if (pdata->filter_init != NULL) { 733 err = pdata->filter_init(pdata, &ts->filter_data); 734 if (err < 0) 735 goto err_free_mem; 736 } 737 ts->filter = pdata->filter; 738 ts->filter_cleanup = pdata->filter_cleanup; 739 } else if (pdata->debounce_max) { 740 ts->debounce_max = pdata->debounce_max; 741 if (ts->debounce_max < 2) 742 ts->debounce_max = 2; 743 ts->debounce_tol = pdata->debounce_tol; 744 ts->debounce_rep = pdata->debounce_rep; 745 ts->filter = ads7846_debounce; 746 ts->filter_data = ts; 747 } else 748 ts->filter = ads7846_no_filter; 749 ts->get_pendown_state = pdata->get_pendown_state; 750 751 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id); 752 753 input_dev->name = "ADS784x Touchscreen"; 754 input_dev->phys = ts->phys; 755 input_dev->cdev.dev = &spi->dev; 756 757 input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS); 758 input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH); 759 input_set_abs_params(input_dev, ABS_X, 760 pdata->x_min ? : 0, 761 pdata->x_max ? : MAX_12BIT, 762 0, 0); 763 input_set_abs_params(input_dev, ABS_Y, 764 pdata->y_min ? : 0, 765 pdata->y_max ? : MAX_12BIT, 766 0, 0); 767 input_set_abs_params(input_dev, ABS_PRESSURE, 768 pdata->pressure_min, pdata->pressure_max, 0, 0); 769 770 /* set up the transfers to read touchscreen state; this assumes we 771 * use formula #2 for pressure, not #3. 772 */ 773 m = &ts->msg[0]; 774 x = ts->xfer; 775 776 spi_message_init(m); 777 778 /* y- still on; turn on only y+ (and ADC) */ 779 ts->read_y = READ_Y; 780 x->tx_buf = &ts->read_y; 781 x->len = 1; 782 spi_message_add_tail(x, m); 783 784 x++; 785 x->rx_buf = &ts->tc.y; 786 x->len = 2; 787 spi_message_add_tail(x, m); 788 789 m->complete = ads7846_rx_val; 790 m->context = ts; 791 792 m++; 793 spi_message_init(m); 794 795 /* turn y- off, x+ on, then leave in lowpower */ 796 x++; 797 ts->read_x = READ_X; 798 x->tx_buf = &ts->read_x; 799 x->len = 1; 800 spi_message_add_tail(x, m); 801 802 x++; 803 x->rx_buf = &ts->tc.x; 804 x->len = 2; 805 spi_message_add_tail(x, m); 806 807 m->complete = ads7846_rx_val; 808 m->context = ts; 809 810 /* turn y+ off, x- on; we'll use formula #2 */ 811 if (ts->model == 7846) { 812 m++; 813 spi_message_init(m); 814 815 x++; 816 ts->read_z1 = READ_Z1; 817 x->tx_buf = &ts->read_z1; 818 x->len = 1; 819 spi_message_add_tail(x, m); 820 821 x++; 822 x->rx_buf = &ts->tc.z1; 823 x->len = 2; 824 spi_message_add_tail(x, m); 825 826 m->complete = ads7846_rx_val; 827 m->context = ts; 828 829 m++; 830 spi_message_init(m); 831 832 x++; 833 ts->read_z2 = READ_Z2; 834 x->tx_buf = &ts->read_z2; 835 x->len = 1; 836 spi_message_add_tail(x, m); 837 838 x++; 839 x->rx_buf = &ts->tc.z2; 840 x->len = 2; 841 spi_message_add_tail(x, m); 842 843 m->complete = ads7846_rx_val; 844 m->context = ts; 845 } 846 847 /* power down */ 848 m++; 849 spi_message_init(m); 850 851 x++; 852 ts->pwrdown = PWRDOWN; 853 x->tx_buf = &ts->pwrdown; 854 x->len = 1; 855 spi_message_add_tail(x, m); 856 857 x++; 858 x->rx_buf = &ts->dummy; 859 x->len = 2; 860 CS_CHANGE(*x); 861 spi_message_add_tail(x, m); 862 863 m->complete = ads7846_rx; 864 m->context = ts; 865 866 ts->last_msg = m; 867 868 if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING, 869 spi->dev.driver->name, ts)) { 870 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); 871 err = -EBUSY; 872 goto err_cleanup_filter; 873 } 874 875 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); 876 877 /* take a first sample, leaving nPENIRQ active; avoid 878 * the touchscreen, in case it's not connected. 879 */ 880 (void) ads7846_read12_ser(&spi->dev, 881 READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON); 882 883 switch (ts->model) { 884 case 7846: 885 ts->attr_group = &ads7846_attr_group; 886 break; 887 case 7845: 888 ts->attr_group = &ads7845_attr_group; 889 break; 890 default: 891 ts->attr_group = &ads7843_attr_group; 892 break; 893 } 894 err = sysfs_create_group(&spi->dev.kobj, ts->attr_group); 895 if (err) 896 goto err_free_irq; 897 898 err = input_register_device(input_dev); 899 if (err) 900 goto err_remove_attr_group; 901 902 return 0; 903 904 err_remove_attr_group: 905 sysfs_remove_group(&spi->dev.kobj, ts->attr_group); 906 err_free_irq: 907 free_irq(spi->irq, ts); 908 err_cleanup_filter: 909 if (ts->filter_cleanup) 910 ts->filter_cleanup(ts->filter_data); 911 err_free_mem: 912 input_free_device(input_dev); 913 kfree(ts); 914 return err; 915 } 916 917 static int __devexit ads7846_remove(struct spi_device *spi) 918 { 919 struct ads7846 *ts = dev_get_drvdata(&spi->dev); 920 921 input_unregister_device(ts->input); 922 923 ads7846_suspend(spi, PMSG_SUSPEND); 924 925 sysfs_remove_group(&spi->dev.kobj, ts->attr_group); 926 927 free_irq(ts->spi->irq, ts); 928 /* suspend left the IRQ disabled */ 929 enable_irq(ts->spi->irq); 930 931 if (ts->filter_cleanup) 932 ts->filter_cleanup(ts->filter_data); 933 934 kfree(ts); 935 936 dev_dbg(&spi->dev, "unregistered touchscreen\n"); 937 return 0; 938 } 939 940 static struct spi_driver ads7846_driver = { 941 .driver = { 942 .name = "ads7846", 943 .bus = &spi_bus_type, 944 .owner = THIS_MODULE, 945 }, 946 .probe = ads7846_probe, 947 .remove = __devexit_p(ads7846_remove), 948 .suspend = ads7846_suspend, 949 .resume = ads7846_resume, 950 }; 951 952 static int __init ads7846_init(void) 953 { 954 /* grr, board-specific init should stay out of drivers!! */ 955 956 #ifdef CONFIG_ARCH_OMAP 957 if (machine_is_omap_osk()) { 958 /* GPIO4 = PENIRQ; GPIO6 = BUSY */ 959 omap_request_gpio(4); 960 omap_set_gpio_direction(4, 1); 961 omap_request_gpio(6); 962 omap_set_gpio_direction(6, 1); 963 } 964 // also TI 1510 Innovator, bitbanging through FPGA 965 // also Nokia 770 966 // also Palm Tungsten T2 967 #endif 968 969 // PXA: 970 // also Dell Axim X50 971 // also HP iPaq H191x/H192x/H415x/H435x 972 // also Intel Lubbock (additional to UCB1400; as temperature sensor) 973 // also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky) 974 975 // Atmel at91sam9261-EK uses ads7843 976 977 // also various AMD Au1x00 devel boards 978 979 return spi_register_driver(&ads7846_driver); 980 } 981 module_init(ads7846_init); 982 983 static void __exit ads7846_exit(void) 984 { 985 spi_unregister_driver(&ads7846_driver); 986 987 #ifdef CONFIG_ARCH_OMAP 988 if (machine_is_omap_osk()) { 989 omap_free_gpio(4); 990 omap_free_gpio(6); 991 } 992 #endif 993 994 } 995 module_exit(ads7846_exit); 996 997 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); 998 MODULE_LICENSE("GPL"); 999