git.oblomov.eu Git - linux-2.6/blob - drivers/staging/meilhaus/me8100_di.c

   1 /**
   2  * @file me8100_di.c
   3  *
   4  * @brief ME-8100 digital input subdevice instance.
   5  * @note Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
   6  * @author Guenter Gebhardt
   7  * @author Krzysztof Gantzke    (k.gantzke@meilhaus.de)
   8  */
   9
  10 /*
  11  * Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
  12  *
  13  * This file is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #ifndef __KERNEL__
  29 #  define __KERNEL__
  30 #endif
  31
  32 /*
  33  * Includes
  34  */
  35 #include <linux/module.h>
  36
  37 #include <linux/slab.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/io.h>
  40 #include <linux/types.h>
  41 #include <linux/interrupt.h>
  42
  43 #include "medefines.h"
  44 #include "meerror.h"
  45
  46 #include "meids.h"
  47 #include "medebug.h"
  48 #include "meplx_reg.h"
  49 #include "me8100_reg.h"
  50 #include "me8100_di_reg.h"
  51 #include "me8100_di.h"
  52
  53 /*
  54  * Defines
  55  */
  56
  57 /*
  58  * Functions
  59  */
  60
  61 static int me8100_di_io_reset_subdevice(struct me_subdevice *subdevice,
  62                                         struct file *filep, int flags)
  63 {
  64         me8100_di_subdevice_t *instance;
  65         unsigned short ctrl;
  66         unsigned long cpu_flags;
  67
  68         PDEBUG("executed.\n");
  69
  70         instance = (me8100_di_subdevice_t *) subdevice;
  71
  72         if (flags) {
  73                 PERROR("Invalid flag specified.\n");
  74                 return ME_ERRNO_INVALID_FLAGS;
  75         }
  76
  77         ME_SUBDEVICE_ENTER;
  78
  79         spin_lock_irqsave(&instance->subdevice_lock, cpu_flags);
  80         spin_lock(instance->ctrl_reg_lock);
  81         ctrl = inw(instance->ctrl_reg);
  82         ctrl &= ~(ME8100_DIO_CTRL_BIT_INTB_1 | ME8100_DIO_CTRL_BIT_INTB_0);
  83         outw(ctrl, instance->ctrl_reg);
  84         PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
  85                    instance->ctrl_reg - instance->reg_base, ctrl);
  86         spin_unlock(instance->ctrl_reg_lock);
  87
  88         outw(0, instance->mask_reg);
  89         PDEBUG_REG("mask_reg outw(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
  90                    instance->mask_reg - instance->reg_base, 0);
  91         outw(0, instance->pattern_reg);
  92         PDEBUG_REG("pattern_reg outw(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
  93                    instance->pattern_reg - instance->reg_base, 0);
  94         instance->rised = -1;
  95         instance->irq_count = 0;
  96         instance->filtering_flag = 0;
  97         spin_unlock_irqrestore(&instance->subdevice_lock, cpu_flags);
  98
  99         outl(PLX_INTCSR_LOCAL_INT1_EN |
 100              PLX_INTCSR_LOCAL_INT1_POL |
 101              PLX_INTCSR_LOCAL_INT2_EN |
 102              PLX_INTCSR_LOCAL_INT2_POL |
 103              PLX_INTCSR_PCI_INT_EN, instance->irq_status_reg);
 104         PDEBUG_REG("plx:irq_status_reg outl(0x%lX)=0x%x\n",
 105                    instance->irq_status_reg,
 106                    PLX_INTCSR_LOCAL_INT1_EN | PLX_INTCSR_LOCAL_INT1_POL |
 107                    PLX_INTCSR_LOCAL_INT2_EN | PLX_INTCSR_LOCAL_INT2_POL |
 108                    PLX_INTCSR_PCI_INT_EN);
 109
 110         wake_up_interruptible_all(&instance->wait_queue);
 111         ME_SUBDEVICE_EXIT;
 112
 113         return ME_ERRNO_SUCCESS;
 114 }
 115
 116 static int me8100_di_io_irq_start(me_subdevice_t *subdevice,
 117                                   struct file *filep,
 118                                   int channel,
 119                                   int irq_source,
 120                                   int irq_edge, int irq_arg, int flags)
 121 {
 122         me8100_di_subdevice_t *instance;
 123         int err = ME_ERRNO_SUCCESS;
 124         uint16_t ctrl;
 125         unsigned long cpu_flags;
 126
 127         PDEBUG("executed.\n");
 128
 129         instance = (me8100_di_subdevice_t *) subdevice;
 130
 131         if (irq_source == ME_IRQ_SOURCE_DIO_PATTERN) {
 132                 if (flags &
 133                     ~(ME_IO_IRQ_START_PATTERN_FILTERING |
 134                       ME_IO_IRQ_START_DIO_WORD)) {
 135                         PERROR("Invalid flag specified.\n");
 136                         return ME_ERRNO_INVALID_FLAGS;
 137                 }
 138
 139                 if (irq_edge != ME_IRQ_EDGE_NOT_USED) {
 140                         PERROR("Invalid irq edge specified.\n");
 141                         return ME_ERRNO_INVALID_IRQ_EDGE;
 142                 }
 143         } else if (irq_source == ME_IRQ_SOURCE_DIO_MASK) {
 144                 if (flags &
 145                     ~(ME_IO_IRQ_START_EXTENDED_STATUS |
 146                       ME_IO_IRQ_START_DIO_WORD)) {
 147                         PERROR("Invalid flag specified.\n");
 148                         return ME_ERRNO_INVALID_FLAGS;
 149                 }
 150
 151                 if (irq_edge != ME_IRQ_EDGE_ANY) {
 152                         PERROR("Invalid irq edge specified.\n");
 153                         return ME_ERRNO_INVALID_IRQ_EDGE;
 154                 }
 155
 156                 if (!(irq_arg & 0xFFFF)) {
 157                         PERROR("No mask specified.\n");
 158                         return ME_ERRNO_INVALID_IRQ_ARG;
 159                 }
 160         } else {
 161                 PERROR("Invalid irq source specified.\n");
 162                 return ME_ERRNO_INVALID_IRQ_SOURCE;
 163         }
 164
 165         if (channel) {
 166                 PERROR("Invalid channel specified.\n");
 167                 return ME_ERRNO_INVALID_CHANNEL;
 168         }
 169
 170         ME_SUBDEVICE_ENTER;
 171
 172         spin_lock_irqsave(&instance->subdevice_lock, cpu_flags);
 173         if (irq_source == ME_IRQ_SOURCE_DIO_PATTERN) {
 174                 outw(irq_arg, instance->pattern_reg);
 175                 instance->compare_value = irq_arg;
 176                 instance->filtering_flag =
 177                     (flags & ME_IO_IRQ_START_PATTERN_FILTERING) ? 1 : 0;
 178         }
 179         if (irq_source == ME_IRQ_SOURCE_DIO_MASK) {
 180                 outw(irq_arg, instance->mask_reg);
 181         }
 182
 183         spin_lock(instance->ctrl_reg_lock);
 184         ctrl = inw(instance->ctrl_reg);
 185         ctrl |= ME8100_DIO_CTRL_BIT_INTB_0;
 186         if (irq_source == ME_IRQ_SOURCE_DIO_PATTERN) {
 187                 ctrl &= ~ME8100_DIO_CTRL_BIT_INTB_1;
 188         }
 189
 190         if (irq_source == ME_IRQ_SOURCE_DIO_MASK) {
 191                 ctrl |= ME8100_DIO_CTRL_BIT_INTB_1;
 192         }
 193         outw(ctrl, instance->ctrl_reg);
 194         PDEBUG_REG("ctrl_reg outw(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
 195                    instance->ctrl_reg - instance->reg_base, ctrl);
 196         spin_unlock(instance->ctrl_reg_lock);
 197
 198         instance->rised = 0;
 199         instance->status_value = 0;
 200         instance->status_value_edges = 0;
 201         instance->line_value = inw(instance->port_reg);
 202         instance->status_flag = flags & ME_IO_IRQ_START_EXTENDED_STATUS;
 203         spin_unlock_irqrestore(&instance->subdevice_lock, cpu_flags);
 204
 205         ME_SUBDEVICE_EXIT;
 206
 207         return err;
 208 }
 209
 210 static int me8100_di_io_irq_wait(me_subdevice_t *subdevice,
 211                                  struct file *filep,
 212                                  int channel,
 213                                  int *irq_count,
 214                                  int *value, int time_out, int flags)
 215 {
 216         me8100_di_subdevice_t *instance;
 217         int err = ME_ERRNO_SUCCESS;
 218         long t = 0;
 219         unsigned long cpu_flags;
 220         int count;
 221
 222         PDEBUG("executed.\n");
 223         PDEVELOP("PID: %d.\n", current->pid);
 224
 225         instance = (me8100_di_subdevice_t *) subdevice;
 226
 227         if (flags &
 228             ~(ME_IO_IRQ_WAIT_NORMAL_STATUS | ME_IO_IRQ_WAIT_EXTENDED_STATUS)) {
 229                 PERROR("Invalid flag specified.\n");
 230                 return ME_ERRNO_INVALID_FLAGS;
 231         }
 232
 233         if (channel) {
 234                 PERROR("Invalid channel specified.\n");
 235                 return ME_ERRNO_INVALID_CHANNEL;
 236         }
 237
 238         if (time_out < 0) {
 239                 PERROR("Invalid time_out specified.\n");
 240                 return ME_ERRNO_INVALID_TIMEOUT;
 241         }
 242
 243         if (time_out) {
 244                 t = (time_out * HZ) / 1000;
 245
 246                 if (t == 0)
 247                         t = 1;
 248         }
 249
 250         ME_SUBDEVICE_ENTER;
 251
 252         if (instance->rised <= 0) {
 253                 instance->rised = 0;
 254                 count = instance->irq_count;
 255
 256                 if (time_out) {
 257                         t = wait_event_interruptible_timeout(instance->
 258                                                              wait_queue,
 259                                                              ((count !=
 260                                                                instance->
 261                                                                irq_count)
 262                                                               || (instance->
 263                                                                   rised < 0)),
 264                                                              t);
 265 //                      t = wait_event_interruptible_timeout(instance->wait_queue, (instance->rised != 0), t);
 266                         if (t == 0) {
 267                                 PERROR("Wait on interrupt timed out.\n");
 268                                 err = ME_ERRNO_TIMEOUT;
 269                         }
 270                 } else {
 271                         wait_event_interruptible(instance->wait_queue,
 272                                                  ((count != instance->irq_count)
 273                                                   || (instance->rised < 0)));
 274 //                      wait_event_interruptible(instance->wait_queue, (instance->rised != 0));
 275                 }
 276
 277                 if (instance->rised < 0) {
 278                         PERROR("Wait on interrupt aborted by user.\n");
 279                         err = ME_ERRNO_CANCELLED;
 280                 }
 281         }
 282
 283         if (signal_pending(current)) {
 284                 PERROR("Wait on interrupt aborted by signal.\n");
 285                 err = ME_ERRNO_SIGNAL;
 286         }
 287
 288         spin_lock_irqsave(&instance->subdevice_lock, cpu_flags);
 289         *irq_count = instance->irq_count;
 290         if (!err) {
 291                 if (flags & ME_IO_IRQ_WAIT_NORMAL_STATUS) {
 292                         *value = instance->status_value;
 293                 } else if (flags & ME_IO_IRQ_WAIT_EXTENDED_STATUS) {
 294                         *value = instance->status_value_edges;
 295                 } else {        // Use default
 296                         if (!instance->status_flag) {
 297                                 *value = instance->status_value;
 298                         } else {
 299                                 *value = instance->status_value_edges;
 300                         }
 301                 }
 302                 instance->rised = 0;
 303 /*
 304                         instance->status_value = 0;
 305                         instance->status_value_edges = 0;
 306 */
 307         } else {
 308                 *value = 0;
 309         }
 310         spin_unlock_irqrestore(&instance->subdevice_lock, cpu_flags);
 311
 312         ME_SUBDEVICE_EXIT;
 313
 314         return err;
 315 }
 316
 317 static int me8100_di_io_irq_stop(me_subdevice_t *subdevice,
 318                                  struct file *filep, int channel, int flags)
 319 {
 320         me8100_di_subdevice_t *instance;
 321         uint16_t ctrl;
 322         unsigned long cpu_flags;
 323
 324         PDEBUG("executed.\n");
 325
 326         instance = (me8100_di_subdevice_t *) subdevice;
 327
 328         if (flags) {
 329                 PERROR("Invalid flag specified.\n");
 330                 return ME_ERRNO_INVALID_FLAGS;
 331         }
 332
 333         if (channel) {
 334                 PERROR("Invalid channel specified.\n");
 335                 return ME_ERRNO_INVALID_CHANNEL;
 336         }
 337
 338         ME_SUBDEVICE_ENTER;
 339
 340         spin_lock_irqsave(&instance->subdevice_lock, cpu_flags);
 341         spin_lock(instance->ctrl_reg_lock);
 342         ctrl = inw(instance->ctrl_reg);
 343         ctrl &= ~(ME8100_DIO_CTRL_BIT_INTB_1 | ME8100_DIO_CTRL_BIT_INTB_0);
 344         outw(ctrl, instance->ctrl_reg);
 345         PDEBUG_REG("ctrl_reg outw(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
 346                    instance->ctrl_reg - instance->reg_base, ctrl);
 347         spin_unlock(instance->ctrl_reg_lock);
 348         instance->rised = -1;
 349         instance->status_value = 0;
 350         instance->status_value_edges = 0;
 351         instance->filtering_flag = 0;
 352         spin_unlock_irqrestore(&instance->subdevice_lock, cpu_flags);
 353         wake_up_interruptible_all(&instance->wait_queue);
 354
 355         ME_SUBDEVICE_EXIT;
 356
 357         return ME_ERRNO_SUCCESS;
 358 }
 359
 360 static int me8100_di_io_single_config(me_subdevice_t *subdevice,
 361                                       struct file *filep,
 362                                       int channel,
 363                                       int single_config,
 364                                       int ref,
 365                                       int trig_chan,
 366                                       int trig_type, int trig_edge, int flags)
 367 {
 368         me8100_di_subdevice_t *instance;
 369         int err = ME_ERRNO_SUCCESS;
 370
 371         PDEBUG("executed.\n");
 372
 373         instance = (me8100_di_subdevice_t *) subdevice;
 374
 375         ME_SUBDEVICE_ENTER;
 376
 377         spin_lock(&instance->subdevice_lock);
 378
 379         switch (flags) {
 380         case ME_IO_SINGLE_CONFIG_NO_FLAGS:
 381         case ME_IO_SINGLE_CONFIG_DIO_WORD:
 382                 if (channel == 0) {
 383                         if (single_config == ME_SINGLE_CONFIG_DIO_INPUT) {
 384                         } else {
 385                                 PERROR
 386                                     ("Invalid port configuration specified.\n");
 387                                 err = ME_ERRNO_INVALID_SINGLE_CONFIG;
 388                         }
 389                 } else {
 390                         PERROR("Invalid channel number.\n");
 391                         err = ME_ERRNO_INVALID_CHANNEL;
 392                 }
 393                 break;
 394
 395         default:
 396                 PERROR("Invalid flags specified.\n");
 397                 err = ME_ERRNO_INVALID_FLAGS;
 398         }
 399
 400         spin_unlock(&instance->subdevice_lock);
 401
 402         ME_SUBDEVICE_EXIT;
 403
 404         return err;
 405 }
 406
 407 static int me8100_di_io_single_read(me_subdevice_t *subdevice,
 408                                     struct file *filep,
 409                                     int channel,
 410                                     int *value, int time_out, int flags)
 411 {
 412         me8100_di_subdevice_t *instance;
 413         int err = ME_ERRNO_SUCCESS;
 414
 415         PDEBUG("executed.\n");
 416
 417         instance = (me8100_di_subdevice_t *) subdevice;
 418
 419         ME_SUBDEVICE_ENTER;
 420
 421         spin_lock(&instance->subdevice_lock);
 422
 423         switch (flags) {
 424
 425         case ME_IO_SINGLE_TYPE_DIO_BIT:
 426                 if ((channel >= 0) && (channel < 16)) {
 427                         *value = inw(instance->port_reg) & (0x1 << channel);
 428                 } else {
 429                         PERROR("Invalid bit number specified.\n");
 430                         err = ME_ERRNO_INVALID_CHANNEL;
 431                 }
 432                 break;
 433
 434         case ME_IO_SINGLE_TYPE_DIO_BYTE:
 435                 if (channel == 0) {
 436                         *value = inw(instance->port_reg) & 0xFF;
 437                 } else if (channel == 1) {
 438                         *value = (inw(instance->port_reg) >> 8) & 0xFF;
 439                 } else {
 440                         PERROR("Invalid byte number specified.\n");
 441                         err = ME_ERRNO_INVALID_CHANNEL;
 442                 }
 443                 break;
 444
 445         case ME_IO_SINGLE_NO_FLAGS:
 446         case ME_IO_SINGLE_TYPE_DIO_WORD:
 447                 if (channel == 0) {
 448                         *value = inw(instance->port_reg);
 449                 } else {
 450                         PERROR("Invalid word number specified.\n");
 451                         err = ME_ERRNO_INVALID_CHANNEL;
 452                 }
 453
 454                 break;
 455
 456         default:
 457                 PERROR("Invalid flags specified.\n");
 458                 err = ME_ERRNO_INVALID_FLAGS;
 459         }
 460
 461         spin_unlock(&instance->subdevice_lock);
 462
 463         ME_SUBDEVICE_EXIT;
 464
 465         return err;
 466 }
 467
 468 static int me8100_di_query_number_channels(me_subdevice_t *subdevice,
 469                                            int *number)
 470 {
 471         PDEBUG("executed.\n");
 472         *number = 16;
 473         return ME_ERRNO_SUCCESS;
 474 }
 475
 476 static int me8100_di_query_subdevice_type(me_subdevice_t *subdevice,
 477                                           int *type, int *subtype)
 478 {
 479         PDEBUG("executed.\n");
 480         *type = ME_TYPE_DI;
 481         *subtype = ME_SUBTYPE_SINGLE;
 482         return ME_ERRNO_SUCCESS;
 483 }
 484
 485 static int me8100_di_query_subdevice_caps(me_subdevice_t *subdevice, int *caps)
 486 {
 487         PDEBUG("executed.\n");
 488         *caps = ME_CAPS_DIO_BIT_PATTERN_IRQ | ME_CAPS_DIO_BIT_MASK_IRQ_EDGE_ANY;
 489         return ME_ERRNO_SUCCESS;
 490 }
 491
 492 static void me8100_di_destructor(struct me_subdevice *subdevice)
 493 {
 494         me8100_di_subdevice_t *instance;
 495
 496         PDEBUG("executed.\n");
 497
 498         instance = (me8100_di_subdevice_t *) subdevice;
 499
 500         free_irq(instance->irq, (void *)instance);
 501         me_subdevice_deinit(&instance->base);
 502         kfree(instance);
 503 }
 504
 505 static irqreturn_t me8100_isr(int irq, void *dev_id)
 506 {
 507         me8100_di_subdevice_t *instance;
 508         uint32_t icsr;
 509
 510         uint16_t irq_status;
 511         uint16_t line_value = 0;
 512
 513         uint32_t status_val = 0;
 514
 515         PDEBUG("executed.\n");
 516
 517         instance = (me8100_di_subdevice_t *) dev_id;
 518
 519         if (irq != instance->irq) {
 520                 PERROR("Incorrect interrupt num: %d.\n", irq);
 521                 return IRQ_NONE;
 522         }
 523
 524         icsr = inl(instance->irq_status_reg);
 525         if (instance->di_idx == 0) {
 526
 527                 if ((icsr &
 528                      (PLX_INTCSR_LOCAL_INT1_STATE | PLX_INTCSR_PCI_INT_EN |
 529                       PLX_INTCSR_LOCAL_INT1_EN)) !=
 530                     (PLX_INTCSR_LOCAL_INT1_STATE | PLX_INTCSR_PCI_INT_EN |
 531                      PLX_INTCSR_LOCAL_INT1_EN)) {
 532                         PINFO
 533                             ("%ld Shared interrupt. %s(): idx=0 plx:irq_status_reg=0x%04X\n",
 534                              jiffies, __func__, icsr);
 535                         return IRQ_NONE;
 536                 }
 537         } else if (instance->di_idx == 1) {
 538                 if ((icsr &
 539                      (PLX_INTCSR_LOCAL_INT2_STATE | PLX_INTCSR_PCI_INT_EN |
 540                       PLX_INTCSR_LOCAL_INT2_EN)) !=
 541                     (PLX_INTCSR_LOCAL_INT2_STATE | PLX_INTCSR_PCI_INT_EN |
 542                      PLX_INTCSR_LOCAL_INT2_EN)) {
 543                         PINFO
 544                             ("%ld Shared interrupt. %s(): idx=1 plx:irq_status_reg=0x%04X\n",
 545                              jiffies, __func__, icsr);
 546                         return IRQ_NONE;
 547                 }
 548         } else {
 549                 PERROR("%s():Wrong interrupt idx=%d csr=0x%X.\n", __func__,
 550                        instance->di_idx, icsr);
 551                 return IRQ_NONE;
 552         }
 553
 554         PDEBUG("me8100_isr():Interrupt from idx=%d occured.\n",
 555                instance->di_idx);
 556         spin_lock(&instance->subdevice_lock);
 557         inw(instance->irq_reset_reg);
 558         line_value = inw(instance->port_reg);
 559
 560         irq_status = instance->line_value ^ line_value;
 561
 562         // Make extended information.
 563         status_val |= (0x00FF & (~(uint16_t) instance->line_value & line_value)) << 16; //Raise
 564         status_val |= (0x00FF & ((uint16_t) instance->line_value & ~line_value));       //Fall
 565
 566         instance->line_value = line_value;
 567
 568         if (instance->rised == 0) {
 569                 instance->status_value = irq_status;
 570                 instance->status_value_edges = status_val;
 571         } else {
 572                 instance->status_value |= irq_status;
 573                 instance->status_value_edges |= status_val;
 574         }
 575
 576         if (instance->filtering_flag) { // For compare mode only.
 577                 if (instance->compare_value == instance->line_value) {
 578                         instance->rised = 1;
 579                         instance->irq_count++;
 580                 }
 581         } else {
 582                 instance->rised = 1;
 583                 instance->irq_count++;
 584         }
 585
 586         spin_unlock(&instance->subdevice_lock);
 587         wake_up_interruptible_all(&instance->wait_queue);
 588
 589         return IRQ_HANDLED;
 590 }
 591
 592 me8100_di_subdevice_t *me8100_di_constructor(uint32_t me8100_reg_base,
 593                                              uint32_t plx_reg_base,
 594                                              unsigned int di_idx,
 595                                              int irq,
 596                                              spinlock_t *ctrl_reg_lock)
 597 {
 598         me8100_di_subdevice_t *subdevice;
 599         int err;
 600
 601         PDEBUG("executed.\n");
 602
 603         /* Allocate memory for subdevice instance */
 604         subdevice = kmalloc(sizeof(me8100_di_subdevice_t), GFP_KERNEL);
 605
 606         if (!subdevice) {
 607                 PERROR("Cannot get memory for subdevice instance.\n");
 608                 return NULL;
 609         }
 610
 611         memset(subdevice, 0, sizeof(me8100_di_subdevice_t));
 612
 613         /* Initialize subdevice base class */
 614         err = me_subdevice_init(&subdevice->base);
 615
 616         if (err) {
 617                 PERROR("Cannot initialize subdevice base class instance.\n");
 618                 kfree(subdevice);
 619                 return NULL;
 620         }
 621         // Initialize spin locks.
 622         spin_lock_init(&subdevice->subdevice_lock);
 623
 624         subdevice->ctrl_reg_lock = ctrl_reg_lock;
 625
 626         /* Save the subdevice index. */
 627         subdevice->di_idx = di_idx;
 628
 629         /* Initialize wait queue */
 630         init_waitqueue_head(&subdevice->wait_queue);
 631
 632         /* Register interrupt service routine. */
 633         subdevice->irq = irq;
 634         err = request_irq(subdevice->irq, me8100_isr,
 635                           IRQF_DISABLED | IRQF_SHARED,
 636                           ME8100_NAME, (void *)subdevice);
 637
 638         if (err) {
 639                 PERROR("Cannot initialize subdevice base class instance.\n");
 640                 kfree(subdevice);
 641                 return NULL;
 642         }
 643         PINFO("Registered irq=%d.\n", subdevice->irq);
 644
 645         /* Initialize the registers */
 646         subdevice->ctrl_reg =
 647             me8100_reg_base + ME8100_CTRL_REG_A + di_idx * ME8100_REG_OFFSET;
 648         subdevice->port_reg =
 649             me8100_reg_base + ME8100_DI_REG_A + di_idx * ME8100_REG_OFFSET;
 650         subdevice->mask_reg =
 651             me8100_reg_base + ME8100_MASK_REG_A + di_idx * ME8100_REG_OFFSET;
 652         subdevice->pattern_reg =
 653             me8100_reg_base + ME8100_PATTERN_REG_A + di_idx * ME8100_REG_OFFSET;
 654         subdevice->din_int_reg =
 655             me8100_reg_base + ME8100_INT_DI_REG_A + di_idx * ME8100_REG_OFFSET;
 656         subdevice->irq_reset_reg =
 657             me8100_reg_base + ME8100_RES_INT_REG_A + di_idx * ME8100_REG_OFFSET;
 658         subdevice->irq_status_reg = plx_reg_base + PLX_INTCSR;
 659 #ifdef MEDEBUG_DEBUG_REG
 660         subdevice->reg_base = me8100_reg_base;
 661 #endif
 662
 663         /* Overload base class methods. */
 664         subdevice->base.me_subdevice_io_irq_start = me8100_di_io_irq_start;
 665         subdevice->base.me_subdevice_io_irq_wait = me8100_di_io_irq_wait;
 666         subdevice->base.me_subdevice_io_irq_stop = me8100_di_io_irq_stop;
 667         subdevice->base.me_subdevice_io_reset_subdevice =
 668             me8100_di_io_reset_subdevice;
 669         subdevice->base.me_subdevice_io_single_config =
 670             me8100_di_io_single_config;
 671         subdevice->base.me_subdevice_io_single_read = me8100_di_io_single_read;
 672         subdevice->base.me_subdevice_query_number_channels =
 673             me8100_di_query_number_channels;
 674         subdevice->base.me_subdevice_query_subdevice_type =
 675             me8100_di_query_subdevice_type;
 676         subdevice->base.me_subdevice_query_subdevice_caps =
 677             me8100_di_query_subdevice_caps;
 678         subdevice->base.me_subdevice_destructor = me8100_di_destructor;
 679
 680         subdevice->rised = 0;
 681         subdevice->irq_count = 0;
 682
 683         return subdevice;
 684 }