drivers/input/serio/hp_sdc.c

   1 /*
   2  * HP i8042-based System Device Controller driver.
   3  *
   4  * Copyright (c) 2001 Brian S. Julin
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions, and the following disclaimer,
  12  *    without modification.
  13  * 2. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * Alternatively, this software may be distributed under the terms of the
  17  * GNU General Public License ("GPL").
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  *
  29  * References:
  30  * System Device Controller Microprocessor Firmware Theory of Operation
  31  *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
  32  * Helge Deller's original hilkbd.c port for PA-RISC.
  33  *
  34  *
  35  * Driver theory of operation:
  36  *
  37  * hp_sdc_put does all writing to the SDC.  ISR can run on a different
  38  * CPU than hp_sdc_put, but only one CPU runs hp_sdc_put at a time
  39  * (it cannot really benefit from SMP anyway.)  A tasket fit this perfectly.
  40  *
  41  * All data coming back from the SDC is sent via interrupt and can be read
  42  * fully in the ISR, so there are no latency/throughput problems there.
  43  * The problem is with output, due to the slow clock speed of the SDC
  44  * compared to the CPU.  This should not be too horrible most of the time,
  45  * but if used with HIL devices that support the multibyte transfer command,
  46  * keeping outbound throughput flowing at the 6500KBps that the HIL is
  47  * capable of is more than can be done at HZ=100.
  48  *
  49  * Busy polling for IBF clear wastes CPU cycles and bus cycles.  hp_sdc.ibf
  50  * is set to 0 when the IBF flag in the status register has cleared.  ISR
  51  * may do this, and may also access the parts of queued transactions related
  52  * to reading data back from the SDC, but otherwise will not touch the
  53  * hp_sdc state. Whenever a register is written hp_sdc.ibf is set to 1.
  54  *
  55  * The i8042 write index and the values in the 4-byte input buffer
  56  * starting at 0x70 are kept track of in hp_sdc.wi, and .r7[], respectively,
  57  * to minimize the amount of IO needed to the SDC.  However these values
  58  * do not need to be locked since they are only ever accessed by hp_sdc_put.
  59  *
  60  * A timer task schedules the tasklet once per second just to make
  61  * sure it doesn't freeze up and to allow for bad reads to time out.
  62  */
  63
  64 #include <linux/hp_sdc.h>
  65 #include <linux/errno.h>
  66 #include <linux/init.h>
  67 #include <linux/module.h>
  68 #include <linux/ioport.h>
  69 #include <linux/time.h>
  70 #include <linux/slab.h>
  71 #include <linux/hil.h>
  72 #include <asm/io.h>
  73 #include <asm/system.h>
  74
  75 /* Machine-specific abstraction */
  76
  77 #if defined(__hppa__)
  78 # include <asm/parisc-device.h>
  79 # define sdc_readb(p)           gsc_readb(p)
  80 # define sdc_writeb(v,p)        gsc_writeb((v),(p))
  81 #elif defined(__mc68000__)
  82 # include <asm/uaccess.h>
  83 # define sdc_readb(p)           in_8(p)
  84 # define sdc_writeb(v,p)        out_8((p),(v))
  85 #else
  86 # error "HIL is not supported on this platform"
  87 #endif
  88
  89 #define PREFIX "HP SDC: "
  90
  91 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
  92 MODULE_DESCRIPTION("HP i8042-based SDC Driver");
  93 MODULE_LICENSE("Dual BSD/GPL");
  94
  95 EXPORT_SYMBOL(hp_sdc_request_timer_irq);
  96 EXPORT_SYMBOL(hp_sdc_request_hil_irq);
  97 EXPORT_SYMBOL(hp_sdc_request_cooked_irq);
  98
  99 EXPORT_SYMBOL(hp_sdc_release_timer_irq);
 100 EXPORT_SYMBOL(hp_sdc_release_hil_irq);
 101 EXPORT_SYMBOL(hp_sdc_release_cooked_irq);
 102
 103 EXPORT_SYMBOL(__hp_sdc_enqueue_transaction);
 104 EXPORT_SYMBOL(hp_sdc_enqueue_transaction);
 105 EXPORT_SYMBOL(hp_sdc_dequeue_transaction);
 106
 107 static hp_i8042_sdc     hp_sdc; /* All driver state is kept in here. */
 108
 109 /*************** primitives for use in any context *********************/
 110 static inline uint8_t hp_sdc_status_in8(void)
 111 {
 112         uint8_t status;
 113         unsigned long flags;
 114
 115         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
 116         status = sdc_readb(hp_sdc.status_io);
 117         if (!(status & HP_SDC_STATUS_IBF))
 118                 hp_sdc.ibf = 0;
 119         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 120
 121         return status;
 122 }
 123
 124 static inline uint8_t hp_sdc_data_in8(void)
 125 {
 126         return sdc_readb(hp_sdc.data_io);
 127 }
 128
 129 static inline void hp_sdc_status_out8(uint8_t val)
 130 {
 131         unsigned long flags;
 132
 133         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
 134         hp_sdc.ibf = 1;
 135         if ((val & 0xf0) == 0xe0)
 136                 hp_sdc.wi = 0xff;
 137         sdc_writeb(val, hp_sdc.status_io);
 138         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 139 }
 140
 141 static inline void hp_sdc_data_out8(uint8_t val)
 142 {
 143         unsigned long flags;
 144
 145         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
 146         hp_sdc.ibf = 1;
 147         sdc_writeb(val, hp_sdc.data_io);
 148         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 149 }
 150
 151 /*      Care must be taken to only invoke hp_sdc_spin_ibf when
 152  *      absolutely needed, or in rarely invoked subroutines.
 153  *      Not only does it waste CPU cycles, it also wastes bus cycles.
 154  */
 155 static inline void hp_sdc_spin_ibf(void)
 156 {
 157         unsigned long flags;
 158         rwlock_t *lock;
 159
 160         lock = &hp_sdc.ibf_lock;
 161
 162         read_lock_irqsave(lock, flags);
 163         if (!hp_sdc.ibf) {
 164                 read_unlock_irqrestore(lock, flags);
 165                 return;
 166         }
 167         read_unlock(lock);
 168         write_lock(lock);
 169         while (sdc_readb(hp_sdc.status_io) & HP_SDC_STATUS_IBF)
 170                 { }
 171         hp_sdc.ibf = 0;
 172         write_unlock_irqrestore(lock, flags);
 173 }
 174
 175
 176 /************************ Interrupt context functions ************************/
 177 static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 178 {
 179         hp_sdc_transaction *curr;
 180
 181         read_lock(&hp_sdc.rtq_lock);
 182         if (hp_sdc.rcurr < 0) {
 183                 read_unlock(&hp_sdc.rtq_lock);
 184                 return;
 185         }
 186         curr = hp_sdc.tq[hp_sdc.rcurr];
 187         read_unlock(&hp_sdc.rtq_lock);
 188
 189         curr->seq[curr->idx++] = status;
 190         curr->seq[curr->idx++] = data;
 191         hp_sdc.rqty -= 2;
 192         do_gettimeofday(&hp_sdc.rtv);
 193
 194         if (hp_sdc.rqty <= 0) {
 195                 /* All data has been gathered. */
 196                 if (curr->seq[curr->actidx] & HP_SDC_ACT_SEMAPHORE)
 197                         if (curr->act.semaphore)
 198                                 up(curr->act.semaphore);
 199
 200                 if (curr->seq[curr->actidx] & HP_SDC_ACT_CALLBACK)
 201                         if (curr->act.irqhook)
 202                                 curr->act.irqhook(irq, dev_id, status, data);
 203
 204                 curr->actidx = curr->idx;
 205                 curr->idx++;
 206                 /* Return control of this transaction */
 207                 write_lock(&hp_sdc.rtq_lock);
 208                 hp_sdc.rcurr = -1;
 209                 hp_sdc.rqty = 0;
 210                 write_unlock(&hp_sdc.rtq_lock);
 211                 tasklet_schedule(&hp_sdc.task);
 212         }
 213 }
 214
 215 static irqreturn_t hp_sdc_isr(int irq, void *dev_id)
 216 {
 217         uint8_t status, data;
 218
 219         status = hp_sdc_status_in8();
 220         /* Read data unconditionally to advance i8042. */
 221         data =   hp_sdc_data_in8();
 222
 223         /* For now we are ignoring these until we get the SDC to behave. */
 224         if (((status & 0xf1) == 0x51) && data == 0x82)
 225                 return IRQ_HANDLED;
 226
 227         switch (status & HP_SDC_STATUS_IRQMASK) {
 228         case 0: /* This case is not documented. */
 229                 break;
 230
 231         case HP_SDC_STATUS_USERTIMER:
 232         case HP_SDC_STATUS_PERIODIC:
 233         case HP_SDC_STATUS_TIMER:
 234                 read_lock(&hp_sdc.hook_lock);
 235                 if (hp_sdc.timer != NULL)
 236                         hp_sdc.timer(irq, dev_id, status, data);
 237                 read_unlock(&hp_sdc.hook_lock);
 238                 break;
 239
 240         case HP_SDC_STATUS_REG:
 241                 hp_sdc_take(irq, dev_id, status, data);
 242                 break;
 243
 244         case HP_SDC_STATUS_HILCMD:
 245         case HP_SDC_STATUS_HILDATA:
 246                 read_lock(&hp_sdc.hook_lock);
 247                 if (hp_sdc.hil != NULL)
 248                         hp_sdc.hil(irq, dev_id, status, data);
 249                 read_unlock(&hp_sdc.hook_lock);
 250                 break;
 251
 252         case HP_SDC_STATUS_PUP:
 253                 read_lock(&hp_sdc.hook_lock);
 254                 if (hp_sdc.pup != NULL)
 255                         hp_sdc.pup(irq, dev_id, status, data);
 256                 else
 257                         printk(KERN_INFO PREFIX "HP SDC reports successful PUP.\n");
 258                 read_unlock(&hp_sdc.hook_lock);
 259                 break;
 260
 261         default:
 262                 read_lock(&hp_sdc.hook_lock);
 263                 if (hp_sdc.cooked != NULL)
 264                         hp_sdc.cooked(irq, dev_id, status, data);
 265                 read_unlock(&hp_sdc.hook_lock);
 266                 break;
 267         }
 268
 269         return IRQ_HANDLED;
 270 }
 271
 272
 273 static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id)
 274 {
 275         int status;
 276
 277         status = hp_sdc_status_in8();
 278         printk(KERN_WARNING PREFIX "NMI !\n");
 279
 280 #if 0
 281         if (status & HP_SDC_NMISTATUS_FHS) {
 282                 read_lock(&hp_sdc.hook_lock);
 283                 if (hp_sdc.timer != NULL)
 284                         hp_sdc.timer(irq, dev_id, status, 0);
 285                 read_unlock(&hp_sdc.hook_lock);
 286         } else {
 287                 /* TODO: pass this on to the HIL handler, or do SAK here? */
 288                 printk(KERN_WARNING PREFIX "HIL NMI\n");
 289         }
 290 #endif
 291
 292         return IRQ_HANDLED;
 293 }
 294
 295
 296 /***************** Kernel (tasklet) context functions ****************/
 297
 298 unsigned long hp_sdc_put(void);
 299
 300 static void hp_sdc_tasklet(unsigned long foo)
 301 {
 302         write_lock_irq(&hp_sdc.rtq_lock);
 303
 304         if (hp_sdc.rcurr >= 0) {
 305                 struct timeval tv;
 306
 307                 do_gettimeofday(&tv);
 308                 if (tv.tv_sec > hp_sdc.rtv.tv_sec)
 309                         tv.tv_usec += USEC_PER_SEC;
 310
 311                 if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
 312                         hp_sdc_transaction *curr;
 313                         uint8_t tmp;
 314
 315                         curr = hp_sdc.tq[hp_sdc.rcurr];
 316                         /* If this turns out to be a normal failure mode
 317                          * we'll need to figure out a way to communicate
 318                          * it back to the application. and be less verbose.
 319                          */
 320                         printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
 321                                tv.tv_usec - hp_sdc.rtv.tv_usec);
 322                         curr->idx += hp_sdc.rqty;
 323                         hp_sdc.rqty = 0;
 324                         tmp = curr->seq[curr->actidx];
 325                         curr->seq[curr->actidx] |= HP_SDC_ACT_DEAD;
 326                         if (tmp & HP_SDC_ACT_SEMAPHORE)
 327                                 if (curr->act.semaphore)
 328                                         up(curr->act.semaphore);
 329
 330                         if (tmp & HP_SDC_ACT_CALLBACK) {
 331                                 /* Note this means that irqhooks may be called
 332                                  * in tasklet/bh context.
 333                                  */
 334                                 if (curr->act.irqhook)
 335                                         curr->act.irqhook(0, NULL, 0, 0);
 336                         }
 337
 338                         curr->actidx = curr->idx;
 339                         curr->idx++;
 340                         hp_sdc.rcurr = -1;
 341                 }
 342         }
 343         write_unlock_irq(&hp_sdc.rtq_lock);
 344         hp_sdc_put();
 345 }
 346
 347 unsigned long hp_sdc_put(void)
 348 {
 349         hp_sdc_transaction *curr;
 350         uint8_t act;
 351         int idx, curridx;
 352
 353         int limit = 0;
 354
 355         write_lock(&hp_sdc.lock);
 356
 357         /* If i8042 buffers are full, we cannot do anything that
 358            requires output, so we skip to the administrativa. */
 359         if (hp_sdc.ibf) {
 360                 hp_sdc_status_in8();
 361                 if (hp_sdc.ibf)
 362                         goto finish;
 363         }
 364
 365  anew:
 366         /* See if we are in the middle of a sequence. */
 367         if (hp_sdc.wcurr < 0)
 368                 hp_sdc.wcurr = 0;
 369         read_lock_irq(&hp_sdc.rtq_lock);
 370         if (hp_sdc.rcurr == hp_sdc.wcurr)
 371                 hp_sdc.wcurr++;
 372         read_unlock_irq(&hp_sdc.rtq_lock);
 373         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 374                 hp_sdc.wcurr = 0;
 375         curridx = hp_sdc.wcurr;
 376
 377         if (hp_sdc.tq[curridx] != NULL)
 378                 goto start;
 379
 380         while (++curridx != hp_sdc.wcurr) {
 381                 if (curridx >= HP_SDC_QUEUE_LEN) {
 382                         curridx = -1; /* Wrap to top */
 383                         continue;
 384                 }
 385                 read_lock_irq(&hp_sdc.rtq_lock);
 386                 if (hp_sdc.rcurr == curridx) {
 387                         read_unlock_irq(&hp_sdc.rtq_lock);
 388                         continue;
 389                 }
 390                 read_unlock_irq(&hp_sdc.rtq_lock);
 391                 if (hp_sdc.tq[curridx] != NULL)
 392                         break; /* Found one. */
 393         }
 394         if (curridx == hp_sdc.wcurr) { /* There's nothing queued to do. */
 395                 curridx = -1;
 396         }
 397         hp_sdc.wcurr = curridx;
 398
 399  start:
 400
 401         /* Check to see if the interrupt mask needs to be set. */
 402         if (hp_sdc.set_im) {
 403                 hp_sdc_status_out8(hp_sdc.im | HP_SDC_CMD_SET_IM);
 404                 hp_sdc.set_im = 0;
 405                 goto finish;
 406         }
 407
 408         if (hp_sdc.wcurr == -1)
 409                 goto done;
 410
 411         curr = hp_sdc.tq[curridx];
 412         idx = curr->actidx;
 413
 414         if (curr->actidx >= curr->endidx) {
 415                 hp_sdc.tq[curridx] = NULL;
 416                 /* Interleave outbound data between the transactions. */
 417                 hp_sdc.wcurr++;
 418                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 419                         hp_sdc.wcurr = 0;
 420                 goto finish;
 421         }
 422
 423         act = curr->seq[idx];
 424         idx++;
 425
 426         if (curr->idx >= curr->endidx) {
 427                 if (act & HP_SDC_ACT_DEALLOC)
 428                         kfree(curr);
 429                 hp_sdc.tq[curridx] = NULL;
 430                 /* Interleave outbound data between the transactions. */
 431                 hp_sdc.wcurr++;
 432                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 433                         hp_sdc.wcurr = 0;
 434                 goto finish;
 435         }
 436
 437         while (act & HP_SDC_ACT_PRECMD) {
 438                 if (curr->idx != idx) {
 439                         idx++;
 440                         act &= ~HP_SDC_ACT_PRECMD;
 441                         break;
 442                 }
 443                 hp_sdc_status_out8(curr->seq[idx]);
 444                 curr->idx++;
 445                 /* act finished? */
 446                 if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_PRECMD)
 447                         goto actdone;
 448                 /* skip quantity field if data-out sequence follows. */
 449                 if (act & HP_SDC_ACT_DATAOUT)
 450                         curr->idx++;
 451                 goto finish;
 452         }
 453         if (act & HP_SDC_ACT_DATAOUT) {
 454                 int qty;
 455
 456                 qty = curr->seq[idx];
 457                 idx++;
 458                 if (curr->idx - idx < qty) {
 459                         hp_sdc_data_out8(curr->seq[curr->idx]);
 460                         curr->idx++;
 461                         /* act finished? */
 462                         if (curr->idx - idx >= qty &&
 463                             (act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT)
 464                                 goto actdone;
 465                         goto finish;
 466                 }
 467                 idx += qty;
 468                 act &= ~HP_SDC_ACT_DATAOUT;
 469         } else
 470             while (act & HP_SDC_ACT_DATAREG) {
 471                 int mask;
 472                 uint8_t w7[4];
 473
 474                 mask = curr->seq[idx];
 475                 if (idx != curr->idx) {
 476                         idx++;
 477                         idx += !!(mask & 1);
 478                         idx += !!(mask & 2);
 479                         idx += !!(mask & 4);
 480                         idx += !!(mask & 8);
 481                         act &= ~HP_SDC_ACT_DATAREG;
 482                         break;
 483                 }
 484
 485                 w7[0] = (mask & 1) ? curr->seq[++idx] : hp_sdc.r7[0];
 486                 w7[1] = (mask & 2) ? curr->seq[++idx] : hp_sdc.r7[1];
 487                 w7[2] = (mask & 4) ? curr->seq[++idx] : hp_sdc.r7[2];
 488                 w7[3] = (mask & 8) ? curr->seq[++idx] : hp_sdc.r7[3];
 489
 490                 if (hp_sdc.wi > 0x73 || hp_sdc.wi < 0x70 ||
 491                     w7[hp_sdc.wi - 0x70] == hp_sdc.r7[hp_sdc.wi - 0x70]) {
 492                         int i = 0;
 493
 494                         /* Need to point the write index register */
 495                         while (i < 4 && w7[i] == hp_sdc.r7[i])
 496                                 i++;
 497
 498                         if (i < 4) {
 499                                 hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
 500                                 hp_sdc.wi = 0x70 + i;
 501                                 goto finish;
 502                         }
 503
 504                         idx++;
 505                         if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
 506                                 goto actdone;
 507
 508                         curr->idx = idx;
 509                         act &= ~HP_SDC_ACT_DATAREG;
 510                         break;
 511                 }
 512
 513                 hp_sdc_data_out8(w7[hp_sdc.wi - 0x70]);
 514                 hp_sdc.r7[hp_sdc.wi - 0x70] = w7[hp_sdc.wi - 0x70];
 515                 hp_sdc.wi++; /* write index register autoincrements */
 516                 {
 517                         int i = 0;
 518
 519                         while ((i < 4) && w7[i] == hp_sdc.r7[i])
 520                                 i++;
 521                         if (i >= 4) {
 522                                 curr->idx = idx + 1;
 523                                 if ((act & HP_SDC_ACT_DURING) ==
 524                                     HP_SDC_ACT_DATAREG)
 525                                         goto actdone;
 526                         }
 527                 }
 528                 goto finish;
 529         }
 530         /* We don't go any further in the command if there is a pending read,
 531            because we don't want interleaved results. */
 532         read_lock_irq(&hp_sdc.rtq_lock);
 533         if (hp_sdc.rcurr >= 0) {
 534                 read_unlock_irq(&hp_sdc.rtq_lock);
 535                 goto finish;
 536         }
 537         read_unlock_irq(&hp_sdc.rtq_lock);
 538
 539
 540         if (act & HP_SDC_ACT_POSTCMD) {
 541                 uint8_t postcmd;
 542
 543                 /* curr->idx should == idx at this point. */
 544                 postcmd = curr->seq[idx];
 545                 curr->idx++;
 546                 if (act & HP_SDC_ACT_DATAIN) {
 547
 548                         /* Start a new read */
 549                         hp_sdc.rqty = curr->seq[curr->idx];
 550                         do_gettimeofday(&hp_sdc.rtv);
 551                         curr->idx++;
 552                         /* Still need to lock here in case of spurious irq. */
 553                         write_lock_irq(&hp_sdc.rtq_lock);
 554                         hp_sdc.rcurr = curridx;
 555                         write_unlock_irq(&hp_sdc.rtq_lock);
 556                         hp_sdc_status_out8(postcmd);
 557                         goto finish;
 558                 }
 559                 hp_sdc_status_out8(postcmd);
 560                 goto actdone;
 561         }
 562
 563  actdone:
 564         if (act & HP_SDC_ACT_SEMAPHORE)
 565                 up(curr->act.semaphore);
 566         else if (act & HP_SDC_ACT_CALLBACK)
 567                 curr->act.irqhook(0,NULL,0,0);
 568
 569         if (curr->idx >= curr->endidx) { /* This transaction is over. */
 570                 if (act & HP_SDC_ACT_DEALLOC)
 571                         kfree(curr);
 572                 hp_sdc.tq[curridx] = NULL;
 573         } else {
 574                 curr->actidx = idx + 1;
 575                 curr->idx = idx + 2;
 576         }
 577         /* Interleave outbound data between the transactions. */
 578         hp_sdc.wcurr++;
 579         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 580                 hp_sdc.wcurr = 0;
 581
 582  finish:
 583         /* If by some quirk IBF has cleared and our ISR has run to
 584            see that that has happened, do it all again. */
 585         if (!hp_sdc.ibf && limit++ < 20)
 586                 goto anew;
 587
 588  done:
 589         if (hp_sdc.wcurr >= 0)
 590                 tasklet_schedule(&hp_sdc.task);
 591         write_unlock(&hp_sdc.lock);
 592
 593         return 0;
 594 }
 595
 596 /******* Functions called in either user or kernel context ****/
 597 int __hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
 598 {
 599         int i;
 600
 601         if (this == NULL) {
 602                 BUG();
 603                 return -EINVAL;
 604         }
 605
 606         /* Can't have same transaction on queue twice */
 607         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
 608                 if (hp_sdc.tq[i] == this)
 609                         goto fail;
 610
 611         this->actidx = 0;
 612         this->idx = 1;
 613
 614         /* Search for empty slot */
 615         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
 616                 if (hp_sdc.tq[i] == NULL) {
 617                         hp_sdc.tq[i] = this;
 618                         tasklet_schedule(&hp_sdc.task);
 619                         return 0;
 620                 }
 621
 622         printk(KERN_WARNING PREFIX "No free slot to add transaction.\n");
 623         return -EBUSY;
 624
 625  fail:
 626         printk(KERN_WARNING PREFIX "Transaction add failed: transaction already queued?\n");
 627         return -EINVAL;
 628 }
 629
 630 int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
 631         unsigned long flags;
 632         int ret;
 633
 634         write_lock_irqsave(&hp_sdc.lock, flags);
 635         ret = __hp_sdc_enqueue_transaction(this);
 636         write_unlock_irqrestore(&hp_sdc.lock,flags);
 637
 638         return ret;
 639 }
 640
 641 int hp_sdc_dequeue_transaction(hp_sdc_transaction *this)
 642 {
 643         unsigned long flags;
 644         int i;
 645
 646         write_lock_irqsave(&hp_sdc.lock, flags);
 647
 648         /* TODO: don't remove it if it's not done. */
 649
 650         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
 651                 if (hp_sdc.tq[i] == this)
 652                         hp_sdc.tq[i] = NULL;
 653
 654         write_unlock_irqrestore(&hp_sdc.lock, flags);
 655         return 0;
 656 }
 657
 658
 659
 660 /********************** User context functions **************************/
 661 int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback)
 662 {
 663         if (callback == NULL || hp_sdc.dev == NULL)
 664                 return -EINVAL;
 665
 666         write_lock_irq(&hp_sdc.hook_lock);
 667         if (hp_sdc.timer != NULL) {
 668                 write_unlock_irq(&hp_sdc.hook_lock);
 669                 return -EBUSY;
 670         }
 671
 672         hp_sdc.timer = callback;
 673         /* Enable interrupts from the timers */
 674         hp_sdc.im &= ~HP_SDC_IM_FH;
 675         hp_sdc.im &= ~HP_SDC_IM_PT;
 676         hp_sdc.im &= ~HP_SDC_IM_TIMERS;
 677         hp_sdc.set_im = 1;
 678         write_unlock_irq(&hp_sdc.hook_lock);
 679
 680         tasklet_schedule(&hp_sdc.task);
 681
 682         return 0;
 683 }
 684
 685 int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback)
 686 {
 687         if (callback == NULL || hp_sdc.dev == NULL)
 688                 return -EINVAL;
 689
 690         write_lock_irq(&hp_sdc.hook_lock);
 691         if (hp_sdc.hil != NULL) {
 692                 write_unlock_irq(&hp_sdc.hook_lock);
 693                 return -EBUSY;
 694         }
 695
 696         hp_sdc.hil = callback;
 697         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 698         hp_sdc.set_im = 1;
 699         write_unlock_irq(&hp_sdc.hook_lock);
 700
 701         tasklet_schedule(&hp_sdc.task);
 702
 703         return 0;
 704 }
 705
 706 int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback)
 707 {
 708         if (callback == NULL || hp_sdc.dev == NULL)
 709                 return -EINVAL;
 710
 711         write_lock_irq(&hp_sdc.hook_lock);
 712         if (hp_sdc.cooked != NULL) {
 713                 write_unlock_irq(&hp_sdc.hook_lock);
 714                 return -EBUSY;
 715         }
 716
 717         /* Enable interrupts from the HIL MLC */
 718         hp_sdc.cooked = callback;
 719         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 720         hp_sdc.set_im = 1;
 721         write_unlock_irq(&hp_sdc.hook_lock);
 722
 723         tasklet_schedule(&hp_sdc.task);
 724
 725         return 0;
 726 }
 727
 728 int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback)
 729 {
 730         write_lock_irq(&hp_sdc.hook_lock);
 731         if ((callback != hp_sdc.timer) ||
 732             (hp_sdc.timer == NULL)) {
 733                 write_unlock_irq(&hp_sdc.hook_lock);
 734                 return -EINVAL;
 735         }
 736
 737         /* Disable interrupts from the timers */
 738         hp_sdc.timer = NULL;
 739         hp_sdc.im |= HP_SDC_IM_TIMERS;
 740         hp_sdc.im |= HP_SDC_IM_FH;
 741         hp_sdc.im |= HP_SDC_IM_PT;
 742         hp_sdc.set_im = 1;
 743         write_unlock_irq(&hp_sdc.hook_lock);
 744         tasklet_schedule(&hp_sdc.task);
 745
 746         return 0;
 747 }
 748
 749 int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback)
 750 {
 751         write_lock_irq(&hp_sdc.hook_lock);
 752         if ((callback != hp_sdc.hil) ||
 753             (hp_sdc.hil == NULL)) {
 754                 write_unlock_irq(&hp_sdc.hook_lock);
 755                 return -EINVAL;
 756         }
 757
 758         hp_sdc.hil = NULL;
 759         /* Disable interrupts from HIL only if there is no cooked driver. */
 760         if(hp_sdc.cooked == NULL) {
 761                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 762                 hp_sdc.set_im = 1;
 763         }
 764         write_unlock_irq(&hp_sdc.hook_lock);
 765         tasklet_schedule(&hp_sdc.task);
 766
 767         return 0;
 768 }
 769
 770 int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback)
 771 {
 772         write_lock_irq(&hp_sdc.hook_lock);
 773         if ((callback != hp_sdc.cooked) ||
 774             (hp_sdc.cooked == NULL)) {
 775                 write_unlock_irq(&hp_sdc.hook_lock);
 776                 return -EINVAL;
 777         }
 778
 779         hp_sdc.cooked = NULL;
 780         /* Disable interrupts from HIL only if there is no raw HIL driver. */
 781         if(hp_sdc.hil == NULL) {
 782                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 783                 hp_sdc.set_im = 1;
 784         }
 785         write_unlock_irq(&hp_sdc.hook_lock);
 786         tasklet_schedule(&hp_sdc.task);
 787
 788         return 0;
 789 }
 790
 791 /************************* Keepalive timer task *********************/
 792
 793 void hp_sdc_kicker (unsigned long data)
 794 {
 795         tasklet_schedule(&hp_sdc.task);
 796         /* Re-insert the periodic task. */
 797         mod_timer(&hp_sdc.kicker, jiffies + HZ);
 798 }
 799
 800 /************************** Module Initialization ***************************/
 801
 802 #if defined(__hppa__)
 803
 804 static const struct parisc_device_id hp_sdc_tbl[] = {
 805         {
 806                 .hw_type =      HPHW_FIO,
 807                 .hversion_rev = HVERSION_REV_ANY_ID,
 808                 .hversion =     HVERSION_ANY_ID,
 809                 .sversion =     0x73,
 810          },
 811         { 0, }
 812 };
 813
 814 MODULE_DEVICE_TABLE(parisc, hp_sdc_tbl);
 815
 816 static int __init hp_sdc_init_hppa(struct parisc_device *d);
 817
 818 static struct parisc_driver hp_sdc_driver = {
 819         .name =         "hp_sdc",
 820         .id_table =     hp_sdc_tbl,
 821         .probe =        hp_sdc_init_hppa,
 822 };
 823
 824 #endif /* __hppa__ */
 825
 826 static int __init hp_sdc_init(void)
 827 {
 828         char *errstr;
 829         hp_sdc_transaction t_sync;
 830         uint8_t ts_sync[6];
 831         struct semaphore s_sync;
 832
 833         rwlock_init(&hp_sdc.lock);
 834         rwlock_init(&hp_sdc.ibf_lock);
 835         rwlock_init(&hp_sdc.rtq_lock);
 836         rwlock_init(&hp_sdc.hook_lock);
 837
 838         hp_sdc.timer            = NULL;
 839         hp_sdc.hil              = NULL;
 840         hp_sdc.pup              = NULL;
 841         hp_sdc.cooked           = NULL;
 842         hp_sdc.im               = HP_SDC_IM_MASK;  /* Mask maskable irqs */
 843         hp_sdc.set_im           = 1;
 844         hp_sdc.wi               = 0xff;
 845         hp_sdc.r7[0]            = 0xff;
 846         hp_sdc.r7[1]            = 0xff;
 847         hp_sdc.r7[2]            = 0xff;
 848         hp_sdc.r7[3]            = 0xff;
 849         hp_sdc.ibf              = 1;
 850
 851         memset(&hp_sdc.tq, 0, sizeof(hp_sdc.tq));
 852
 853         hp_sdc.wcurr            = -1;
 854         hp_sdc.rcurr            = -1;
 855         hp_sdc.rqty             = 0;
 856
 857         hp_sdc.dev_err = -ENODEV;
 858
 859         errstr = "IO not found for";
 860         if (!hp_sdc.base_io)
 861                 goto err0;
 862
 863         errstr = "IRQ not found for";
 864         if (!hp_sdc.irq)
 865                 goto err0;
 866
 867         hp_sdc.dev_err = -EBUSY;
 868
 869 #if defined(__hppa__)
 870         errstr = "IO not available for";
 871         if (request_region(hp_sdc.data_io, 2, hp_sdc_driver.name))
 872                 goto err0;
 873 #endif
 874
 875         errstr = "IRQ not available for";
 876         if (request_irq(hp_sdc.irq, &hp_sdc_isr, IRQF_SHARED|IRQF_SAMPLE_RANDOM,
 877                         "HP SDC", &hp_sdc))
 878                 goto err1;
 879
 880         errstr = "NMI not available for";
 881         if (request_irq(hp_sdc.nmi, &hp_sdc_nmisr, IRQF_SHARED,
 882                         "HP SDC NMI", &hp_sdc))
 883                 goto err2;
 884
 885         printk(KERN_INFO PREFIX "HP SDC at 0x%p, IRQ %d (NMI IRQ %d)\n",
 886                (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
 887
 888         hp_sdc_status_in8();
 889         hp_sdc_data_in8();
 890
 891         tasklet_init(&hp_sdc.task, hp_sdc_tasklet, 0);
 892
 893         /* Sync the output buffer registers, thus scheduling hp_sdc_tasklet. */
 894         t_sync.actidx   = 0;
 895         t_sync.idx      = 1;
 896         t_sync.endidx   = 6;
 897         t_sync.seq      = ts_sync;
 898         ts_sync[0]      = HP_SDC_ACT_DATAREG | HP_SDC_ACT_SEMAPHORE;
 899         ts_sync[1]      = 0x0f;
 900         ts_sync[2] = ts_sync[3] = ts_sync[4] = ts_sync[5] = 0;
 901         t_sync.act.semaphore = &s_sync;
 902         init_MUTEX_LOCKED(&s_sync);
 903         hp_sdc_enqueue_transaction(&t_sync);
 904         down(&s_sync); /* Wait for t_sync to complete */
 905
 906         /* Create the keepalive task */
 907         init_timer(&hp_sdc.kicker);
 908         hp_sdc.kicker.expires = jiffies + HZ;
 909         hp_sdc.kicker.function = &hp_sdc_kicker;
 910         add_timer(&hp_sdc.kicker);
 911
 912         hp_sdc.dev_err = 0;
 913         return 0;
 914  err2:
 915         free_irq(hp_sdc.irq, &hp_sdc);
 916  err1:
 917         release_region(hp_sdc.data_io, 2);
 918  err0:
 919         printk(KERN_WARNING PREFIX ": %s SDC IO=0x%p IRQ=0x%x NMI=0x%x\n",
 920                 errstr, (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
 921         hp_sdc.dev = NULL;
 922
 923         return hp_sdc.dev_err;
 924 }
 925
 926 #if defined(__hppa__)
 927
 928 static int __init hp_sdc_init_hppa(struct parisc_device *d)
 929 {
 930         if (!d)
 931                 return 1;
 932         if (hp_sdc.dev != NULL)
 933                 return 1;       /* We only expect one SDC */
 934
 935         hp_sdc.dev              = d;
 936         hp_sdc.irq              = d->irq;
 937         hp_sdc.nmi              = d->aux_irq;
 938         hp_sdc.base_io          = d->hpa.start;
 939         hp_sdc.data_io          = d->hpa.start + 0x800;
 940         hp_sdc.status_io        = d->hpa.start + 0x801;
 941
 942         return hp_sdc_init();
 943 }
 944
 945 #endif /* __hppa__ */
 946
 947 static void hp_sdc_exit(void)
 948 {
 949         write_lock_irq(&hp_sdc.lock);
 950
 951         /* Turn off all maskable "sub-function" irq's. */
 952         hp_sdc_spin_ibf();
 953         sdc_writeb(HP_SDC_CMD_SET_IM | HP_SDC_IM_MASK, hp_sdc.status_io);
 954
 955         /* Wait until we know this has been processed by the i8042 */
 956         hp_sdc_spin_ibf();
 957
 958         free_irq(hp_sdc.nmi, &hp_sdc);
 959         free_irq(hp_sdc.irq, &hp_sdc);
 960         write_unlock_irq(&hp_sdc.lock);
 961
 962         del_timer(&hp_sdc.kicker);
 963
 964         tasklet_kill(&hp_sdc.task);
 965
 966 #if defined(__hppa__)
 967         if (unregister_parisc_driver(&hp_sdc_driver))
 968                 printk(KERN_WARNING PREFIX "Error unregistering HP SDC");
 969 #endif
 970 }
 971
 972 static int __init hp_sdc_register(void)
 973 {
 974         hp_sdc_transaction tq_init;
 975         uint8_t tq_init_seq[5];
 976         struct semaphore tq_init_sem;
 977 #if defined(__mc68000__)
 978         mm_segment_t fs;
 979         unsigned char i;
 980 #endif
 981
 982         hp_sdc.dev = NULL;
 983         hp_sdc.dev_err = 0;
 984 #if defined(__hppa__)
 985         if (register_parisc_driver(&hp_sdc_driver)) {
 986                 printk(KERN_WARNING PREFIX "Error registering SDC with system bus tree.\n");
 987                 return -ENODEV;
 988         }
 989 #elif defined(__mc68000__)
 990         if (!MACH_IS_HP300)
 991             return -ENODEV;
 992
 993         hp_sdc.irq       = 1;
 994         hp_sdc.nmi       = 7;
 995         hp_sdc.base_io   = (unsigned long) 0xf0428000;
 996         hp_sdc.data_io   = (unsigned long) hp_sdc.base_io + 1;
 997         hp_sdc.status_io = (unsigned long) hp_sdc.base_io + 3;
 998         fs = get_fs();
 999         set_fs(KERNEL_DS);
1000         if (!get_user(i, (unsigned char *)hp_sdc.data_io))
1001                 hp_sdc.dev = (void *)1;
1002         set_fs(fs);
1003         hp_sdc.dev_err   = hp_sdc_init();
1004 #endif
1005         if (hp_sdc.dev == NULL) {
1006                 printk(KERN_WARNING PREFIX "No SDC found.\n");
1007                 return hp_sdc.dev_err;
1008         }
1009
1010         init_MUTEX_LOCKED(&tq_init_sem);
1011
1012         tq_init.actidx          = 0;
1013         tq_init.idx             = 1;
1014         tq_init.endidx          = 5;
1015         tq_init.seq             = tq_init_seq;
1016         tq_init.act.semaphore   = &tq_init_sem;
1017
1018         tq_init_seq[0] =
1019                 HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
1020         tq_init_seq[1] = HP_SDC_CMD_READ_KCC;
1021         tq_init_seq[2] = 1;
1022         tq_init_seq[3] = 0;
1023         tq_init_seq[4] = 0;
1024
1025         hp_sdc_enqueue_transaction(&tq_init);
1026
1027         down(&tq_init_sem);
1028         up(&tq_init_sem);
1029
1030         if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
1031                 printk(KERN_WARNING PREFIX "Error reading config byte.\n");
1032                 hp_sdc_exit();
1033                 return -ENODEV;
1034         }
1035         hp_sdc.r11 = tq_init_seq[4];
1036         if (hp_sdc.r11 & HP_SDC_CFG_NEW) {
1037                 const char *str;
1038                 printk(KERN_INFO PREFIX "New style SDC\n");
1039                 tq_init_seq[1] = HP_SDC_CMD_READ_XTD;
1040                 tq_init.actidx          = 0;
1041                 tq_init.idx             = 1;
1042                 down(&tq_init_sem);
1043                 hp_sdc_enqueue_transaction(&tq_init);
1044                 down(&tq_init_sem);
1045                 up(&tq_init_sem);
1046                 if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
1047                         printk(KERN_WARNING PREFIX "Error reading extended config byte.\n");
1048                         return -ENODEV;
1049                 }
1050                 hp_sdc.r7e = tq_init_seq[4];
1051                 HP_SDC_XTD_REV_STRINGS(hp_sdc.r7e & HP_SDC_XTD_REV, str)
1052                 printk(KERN_INFO PREFIX "Revision: %s\n", str);
1053                 if (hp_sdc.r7e & HP_SDC_XTD_BEEPER)
1054                         printk(KERN_INFO PREFIX "TI SN76494 beeper present\n");
1055                 if (hp_sdc.r7e & HP_SDC_XTD_BBRTC)
1056                         printk(KERN_INFO PREFIX "OKI MSM-58321 BBRTC present\n");
1057                 printk(KERN_INFO PREFIX "Spunking the self test register to force PUP "
1058                        "on next firmware reset.\n");
1059                 tq_init_seq[0] = HP_SDC_ACT_PRECMD |
1060                         HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
1061                 tq_init_seq[1] = HP_SDC_CMD_SET_STR;
1062                 tq_init_seq[2] = 1;
1063                 tq_init_seq[3] = 0;
1064                 tq_init.actidx          = 0;
1065                 tq_init.idx             = 1;
1066                 tq_init.endidx          = 4;
1067                 down(&tq_init_sem);
1068                 hp_sdc_enqueue_transaction(&tq_init);
1069                 down(&tq_init_sem);
1070                 up(&tq_init_sem);
1071         } else
1072                 printk(KERN_INFO PREFIX "Old style SDC (1820-%s).\n",
1073                        (hp_sdc.r11 & HP_SDC_CFG_REV) ? "3300" : "2564/3087");
1074
1075         return 0;
1076 }
1077
1078 module_init(hp_sdc_register);
1079 module_exit(hp_sdc_exit);
1080
1081 /* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64)
1082  *                                              cycles cycles-adj    time
1083  * between two consecutive mfctl(16)'s:              4        n/a    63ns
1084  * hp_sdc_spin_ibf when idle:                      119        115   1.7us
1085  * gsc_writeb status register:                      83         79   1.2us
1086  * IBF to clear after sending SET_IM:             6204       6006    93us
1087  * IBF to clear after sending LOAD_RT:            4467       4352    68us
1088  * IBF to clear after sending two LOAD_RTs:      18974      18859   295us
1089  * READ_T1, read status/data, IRQ, call handler: 35564        n/a   556us
1090  * cmd to ~IBF READ_T1 2nd time right after:   5158403        n/a    81ms
1091  * between IRQ received and ~IBF for above:    2578877        n/a    40ms
1092  *
1093  * Performance stats after a run of this module configuring HIL and
1094  * receiving a few mouse events:
1095  *
1096  * status in8  282508 cycles 7128 calls
1097  * status out8   8404 cycles  341 calls
1098  * data out8     1734 cycles   78 calls
1099  * isr         174324 cycles  617 calls (includes take)
1100  * take          1241 cycles    2 calls
1101  * put        1411504 cycles 6937 calls
1102  * task       1655209 cycles 6937 calls (includes put)
1103  *
1104  */