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/semaphore.h>
  71 #include <linux/slab.h>
  72 #include <linux/hil.h>
  73 #include <asm/io.h>
  74 #include <asm/system.h>
  75
  76 /* Machine-specific abstraction */
  77
  78 #if defined(__hppa__)
  79 # include <asm/parisc-device.h>
  80 # define sdc_readb(p)           gsc_readb(p)
  81 # define sdc_writeb(v,p)        gsc_writeb((v),(p))
  82 #elif defined(__mc68000__)
  83 # include <asm/uaccess.h>
  84 # define sdc_readb(p)           in_8(p)
  85 # define sdc_writeb(v,p)        out_8((p),(v))
  86 #else
  87 # error "HIL is not supported on this platform"
  88 #endif
  89
  90 #define PREFIX "HP SDC: "
  91
  92 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
  93 MODULE_DESCRIPTION("HP i8042-based SDC Driver");
  94 MODULE_LICENSE("Dual BSD/GPL");
  95
  96 EXPORT_SYMBOL(hp_sdc_request_timer_irq);
  97 EXPORT_SYMBOL(hp_sdc_request_hil_irq);
  98 EXPORT_SYMBOL(hp_sdc_request_cooked_irq);
  99
 100 EXPORT_SYMBOL(hp_sdc_release_timer_irq);
 101 EXPORT_SYMBOL(hp_sdc_release_hil_irq);
 102 EXPORT_SYMBOL(hp_sdc_release_cooked_irq);
 103
 104 EXPORT_SYMBOL(__hp_sdc_enqueue_transaction);
 105 EXPORT_SYMBOL(hp_sdc_enqueue_transaction);
 106 EXPORT_SYMBOL(hp_sdc_dequeue_transaction);
 107
 108 static unsigned int hp_sdc_disabled;
 109 module_param_named(no_hpsdc, hp_sdc_disabled, bool, 0);
 110 MODULE_PARM_DESC(no_hpsdc, "Do not enable HP SDC driver.");
 111
 112 static hp_i8042_sdc     hp_sdc; /* All driver state is kept in here. */
 113
 114 /*************** primitives for use in any context *********************/
 115 static inline uint8_t hp_sdc_status_in8(void)
 116 {
 117         uint8_t status;
 118         unsigned long flags;
 119
 120         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
 121         status = sdc_readb(hp_sdc.status_io);
 122         if (!(status & HP_SDC_STATUS_IBF))
 123                 hp_sdc.ibf = 0;
 124         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 125
 126         return status;
 127 }
 128
 129 static inline uint8_t hp_sdc_data_in8(void)
 130 {
 131         return sdc_readb(hp_sdc.data_io);
 132 }
 133
 134 static inline void hp_sdc_status_out8(uint8_t val)
 135 {
 136         unsigned long flags;
 137
 138         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
 139         hp_sdc.ibf = 1;
 140         if ((val & 0xf0) == 0xe0)
 141                 hp_sdc.wi = 0xff;
 142         sdc_writeb(val, hp_sdc.status_io);
 143         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 144 }
 145
 146 static inline void hp_sdc_data_out8(uint8_t val)
 147 {
 148         unsigned long flags;
 149
 150         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
 151         hp_sdc.ibf = 1;
 152         sdc_writeb(val, hp_sdc.data_io);
 153         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 154 }
 155
 156 /*      Care must be taken to only invoke hp_sdc_spin_ibf when
 157  *      absolutely needed, or in rarely invoked subroutines.
 158  *      Not only does it waste CPU cycles, it also wastes bus cycles.
 159  */
 160 static inline void hp_sdc_spin_ibf(void)
 161 {
 162         unsigned long flags;
 163         rwlock_t *lock;
 164
 165         lock = &hp_sdc.ibf_lock;
 166
 167         read_lock_irqsave(lock, flags);
 168         if (!hp_sdc.ibf) {
 169                 read_unlock_irqrestore(lock, flags);
 170                 return;
 171         }
 172         read_unlock(lock);
 173         write_lock(lock);
 174         while (sdc_readb(hp_sdc.status_io) & HP_SDC_STATUS_IBF)
 175                 { }
 176         hp_sdc.ibf = 0;
 177         write_unlock_irqrestore(lock, flags);
 178 }
 179
 180
 181 /************************ Interrupt context functions ************************/
 182 static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
 183 {
 184         hp_sdc_transaction *curr;
 185
 186         read_lock(&hp_sdc.rtq_lock);
 187         if (hp_sdc.rcurr < 0) {
 188                 read_unlock(&hp_sdc.rtq_lock);
 189                 return;
 190         }
 191         curr = hp_sdc.tq[hp_sdc.rcurr];
 192         read_unlock(&hp_sdc.rtq_lock);
 193
 194         curr->seq[curr->idx++] = status;
 195         curr->seq[curr->idx++] = data;
 196         hp_sdc.rqty -= 2;
 197         do_gettimeofday(&hp_sdc.rtv);
 198
 199         if (hp_sdc.rqty <= 0) {
 200                 /* All data has been gathered. */
 201                 if (curr->seq[curr->actidx] & HP_SDC_ACT_SEMAPHORE)
 202                         if (curr->act.semaphore)
 203                                 up(curr->act.semaphore);
 204
 205                 if (curr->seq[curr->actidx] & HP_SDC_ACT_CALLBACK)
 206                         if (curr->act.irqhook)
 207                                 curr->act.irqhook(irq, dev_id, status, data);
 208
 209                 curr->actidx = curr->idx;
 210                 curr->idx++;
 211                 /* Return control of this transaction */
 212                 write_lock(&hp_sdc.rtq_lock);
 213                 hp_sdc.rcurr = -1;
 214                 hp_sdc.rqty = 0;
 215                 write_unlock(&hp_sdc.rtq_lock);
 216                 tasklet_schedule(&hp_sdc.task);
 217         }
 218 }
 219
 220 static irqreturn_t hp_sdc_isr(int irq, void *dev_id)
 221 {
 222         uint8_t status, data;
 223
 224         status = hp_sdc_status_in8();
 225         /* Read data unconditionally to advance i8042. */
 226         data =   hp_sdc_data_in8();
 227
 228         /* For now we are ignoring these until we get the SDC to behave. */
 229         if (((status & 0xf1) == 0x51) && data == 0x82)
 230                 return IRQ_HANDLED;
 231
 232         switch (status & HP_SDC_STATUS_IRQMASK) {
 233         case 0: /* This case is not documented. */
 234                 break;
 235
 236         case HP_SDC_STATUS_USERTIMER:
 237         case HP_SDC_STATUS_PERIODIC:
 238         case HP_SDC_STATUS_TIMER:
 239                 read_lock(&hp_sdc.hook_lock);
 240                 if (hp_sdc.timer != NULL)
 241                         hp_sdc.timer(irq, dev_id, status, data);
 242                 read_unlock(&hp_sdc.hook_lock);
 243                 break;
 244
 245         case HP_SDC_STATUS_REG:
 246                 hp_sdc_take(irq, dev_id, status, data);
 247                 break;
 248
 249         case HP_SDC_STATUS_HILCMD:
 250         case HP_SDC_STATUS_HILDATA:
 251                 read_lock(&hp_sdc.hook_lock);
 252                 if (hp_sdc.hil != NULL)
 253                         hp_sdc.hil(irq, dev_id, status, data);
 254                 read_unlock(&hp_sdc.hook_lock);
 255                 break;
 256
 257         case HP_SDC_STATUS_PUP:
 258                 read_lock(&hp_sdc.hook_lock);
 259                 if (hp_sdc.pup != NULL)
 260                         hp_sdc.pup(irq, dev_id, status, data);
 261                 else
 262                         printk(KERN_INFO PREFIX "HP SDC reports successful PUP.\n");
 263                 read_unlock(&hp_sdc.hook_lock);
 264                 break;
 265
 266         default:
 267                 read_lock(&hp_sdc.hook_lock);
 268                 if (hp_sdc.cooked != NULL)
 269                         hp_sdc.cooked(irq, dev_id, status, data);
 270                 read_unlock(&hp_sdc.hook_lock);
 271                 break;
 272         }
 273
 274         return IRQ_HANDLED;
 275 }
 276
 277
 278 static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id)
 279 {
 280         int status;
 281
 282         status = hp_sdc_status_in8();
 283         printk(KERN_WARNING PREFIX "NMI !\n");
 284
 285 #if 0
 286         if (status & HP_SDC_NMISTATUS_FHS) {
 287                 read_lock(&hp_sdc.hook_lock);
 288                 if (hp_sdc.timer != NULL)
 289                         hp_sdc.timer(irq, dev_id, status, 0);
 290                 read_unlock(&hp_sdc.hook_lock);
 291         } else {
 292                 /* TODO: pass this on to the HIL handler, or do SAK here? */
 293                 printk(KERN_WARNING PREFIX "HIL NMI\n");
 294         }
 295 #endif
 296
 297         return IRQ_HANDLED;
 298 }
 299
 300
 301 /***************** Kernel (tasklet) context functions ****************/
 302
 303 unsigned long hp_sdc_put(void);
 304
 305 static void hp_sdc_tasklet(unsigned long foo)
 306 {
 307         write_lock_irq(&hp_sdc.rtq_lock);
 308
 309         if (hp_sdc.rcurr >= 0) {
 310                 struct timeval tv;
 311
 312                 do_gettimeofday(&tv);
 313                 if (tv.tv_sec > hp_sdc.rtv.tv_sec)
 314                         tv.tv_usec += USEC_PER_SEC;
 315
 316                 if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
 317                         hp_sdc_transaction *curr;
 318                         uint8_t tmp;
 319
 320                         curr = hp_sdc.tq[hp_sdc.rcurr];
 321                         /* If this turns out to be a normal failure mode
 322                          * we'll need to figure out a way to communicate
 323                          * it back to the application. and be less verbose.
 324                          */
 325                         printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
 326                                tv.tv_usec - hp_sdc.rtv.tv_usec);
 327                         curr->idx += hp_sdc.rqty;
 328                         hp_sdc.rqty = 0;
 329                         tmp = curr->seq[curr->actidx];
 330                         curr->seq[curr->actidx] |= HP_SDC_ACT_DEAD;
 331                         if (tmp & HP_SDC_ACT_SEMAPHORE)
 332                                 if (curr->act.semaphore)
 333                                         up(curr->act.semaphore);
 334
 335                         if (tmp & HP_SDC_ACT_CALLBACK) {
 336                                 /* Note this means that irqhooks may be called
 337                                  * in tasklet/bh context.
 338                                  */
 339                                 if (curr->act.irqhook)
 340                                         curr->act.irqhook(0, NULL, 0, 0);
 341                         }
 342
 343                         curr->actidx = curr->idx;
 344                         curr->idx++;
 345                         hp_sdc.rcurr = -1;
 346                 }
 347         }
 348         write_unlock_irq(&hp_sdc.rtq_lock);
 349         hp_sdc_put();
 350 }
 351
 352 unsigned long hp_sdc_put(void)
 353 {
 354         hp_sdc_transaction *curr;
 355         uint8_t act;
 356         int idx, curridx;
 357
 358         int limit = 0;
 359
 360         write_lock(&hp_sdc.lock);
 361
 362         /* If i8042 buffers are full, we cannot do anything that
 363            requires output, so we skip to the administrativa. */
 364         if (hp_sdc.ibf) {
 365                 hp_sdc_status_in8();
 366                 if (hp_sdc.ibf)
 367                         goto finish;
 368         }
 369
 370  anew:
 371         /* See if we are in the middle of a sequence. */
 372         if (hp_sdc.wcurr < 0)
 373                 hp_sdc.wcurr = 0;
 374         read_lock_irq(&hp_sdc.rtq_lock);
 375         if (hp_sdc.rcurr == hp_sdc.wcurr)
 376                 hp_sdc.wcurr++;
 377         read_unlock_irq(&hp_sdc.rtq_lock);
 378         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 379                 hp_sdc.wcurr = 0;
 380         curridx = hp_sdc.wcurr;
 381
 382         if (hp_sdc.tq[curridx] != NULL)
 383                 goto start;
 384
 385         while (++curridx != hp_sdc.wcurr) {
 386                 if (curridx >= HP_SDC_QUEUE_LEN) {
 387                         curridx = -1; /* Wrap to top */
 388                         continue;
 389                 }
 390                 read_lock_irq(&hp_sdc.rtq_lock);
 391                 if (hp_sdc.rcurr == curridx) {
 392                         read_unlock_irq(&hp_sdc.rtq_lock);
 393                         continue;
 394                 }
 395                 read_unlock_irq(&hp_sdc.rtq_lock);
 396                 if (hp_sdc.tq[curridx] != NULL)
 397                         break; /* Found one. */
 398         }
 399         if (curridx == hp_sdc.wcurr) { /* There's nothing queued to do. */
 400                 curridx = -1;
 401         }
 402         hp_sdc.wcurr = curridx;
 403
 404  start:
 405
 406         /* Check to see if the interrupt mask needs to be set. */
 407         if (hp_sdc.set_im) {
 408                 hp_sdc_status_out8(hp_sdc.im | HP_SDC_CMD_SET_IM);
 409                 hp_sdc.set_im = 0;
 410                 goto finish;
 411         }
 412
 413         if (hp_sdc.wcurr == -1)
 414                 goto done;
 415
 416         curr = hp_sdc.tq[curridx];
 417         idx = curr->actidx;
 418
 419         if (curr->actidx >= curr->endidx) {
 420                 hp_sdc.tq[curridx] = NULL;
 421                 /* Interleave outbound data between the transactions. */
 422                 hp_sdc.wcurr++;
 423                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 424                         hp_sdc.wcurr = 0;
 425                 goto finish;
 426         }
 427
 428         act = curr->seq[idx];
 429         idx++;
 430
 431         if (curr->idx >= curr->endidx) {
 432                 if (act & HP_SDC_ACT_DEALLOC)
 433                         kfree(curr);
 434                 hp_sdc.tq[curridx] = NULL;
 435                 /* Interleave outbound data between the transactions. */
 436                 hp_sdc.wcurr++;
 437                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 438                         hp_sdc.wcurr = 0;
 439                 goto finish;
 440         }
 441
 442         while (act & HP_SDC_ACT_PRECMD) {
 443                 if (curr->idx != idx) {
 444                         idx++;
 445                         act &= ~HP_SDC_ACT_PRECMD;
 446                         break;
 447                 }
 448                 hp_sdc_status_out8(curr->seq[idx]);
 449                 curr->idx++;
 450                 /* act finished? */
 451                 if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_PRECMD)
 452                         goto actdone;
 453                 /* skip quantity field if data-out sequence follows. */
 454                 if (act & HP_SDC_ACT_DATAOUT)
 455                         curr->idx++;
 456                 goto finish;
 457         }
 458         if (act & HP_SDC_ACT_DATAOUT) {
 459                 int qty;
 460
 461                 qty = curr->seq[idx];
 462                 idx++;
 463                 if (curr->idx - idx < qty) {
 464                         hp_sdc_data_out8(curr->seq[curr->idx]);
 465                         curr->idx++;
 466                         /* act finished? */
 467                         if (curr->idx - idx >= qty &&
 468                             (act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT)
 469                                 goto actdone;
 470                         goto finish;
 471                 }
 472                 idx += qty;
 473                 act &= ~HP_SDC_ACT_DATAOUT;
 474         } else
 475             while (act & HP_SDC_ACT_DATAREG) {
 476                 int mask;
 477                 uint8_t w7[4];
 478
 479                 mask = curr->seq[idx];
 480                 if (idx != curr->idx) {
 481                         idx++;
 482                         idx += !!(mask & 1);
 483                         idx += !!(mask & 2);
 484                         idx += !!(mask & 4);
 485                         idx += !!(mask & 8);
 486                         act &= ~HP_SDC_ACT_DATAREG;
 487                         break;
 488                 }
 489
 490                 w7[0] = (mask & 1) ? curr->seq[++idx] : hp_sdc.r7[0];
 491                 w7[1] = (mask & 2) ? curr->seq[++idx] : hp_sdc.r7[1];
 492                 w7[2] = (mask & 4) ? curr->seq[++idx] : hp_sdc.r7[2];
 493                 w7[3] = (mask & 8) ? curr->seq[++idx] : hp_sdc.r7[3];
 494
 495                 if (hp_sdc.wi > 0x73 || hp_sdc.wi < 0x70 ||
 496                     w7[hp_sdc.wi - 0x70] == hp_sdc.r7[hp_sdc.wi - 0x70]) {
 497                         int i = 0;
 498
 499                         /* Need to point the write index register */
 500                         while (i < 4 && w7[i] == hp_sdc.r7[i])
 501                                 i++;
 502
 503                         if (i < 4) {
 504                                 hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
 505                                 hp_sdc.wi = 0x70 + i;
 506                                 goto finish;
 507                         }
 508
 509                         idx++;
 510                         if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
 511                                 goto actdone;
 512
 513                         curr->idx = idx;
 514                         act &= ~HP_SDC_ACT_DATAREG;
 515                         break;
 516                 }
 517
 518                 hp_sdc_data_out8(w7[hp_sdc.wi - 0x70]);
 519                 hp_sdc.r7[hp_sdc.wi - 0x70] = w7[hp_sdc.wi - 0x70];
 520                 hp_sdc.wi++; /* write index register autoincrements */
 521                 {
 522                         int i = 0;
 523
 524                         while ((i < 4) && w7[i] == hp_sdc.r7[i])
 525                                 i++;
 526                         if (i >= 4) {
 527                                 curr->idx = idx + 1;
 528                                 if ((act & HP_SDC_ACT_DURING) ==
 529                                     HP_SDC_ACT_DATAREG)
 530                                         goto actdone;
 531                         }
 532                 }
 533                 goto finish;
 534         }
 535         /* We don't go any further in the command if there is a pending read,
 536            because we don't want interleaved results. */
 537         read_lock_irq(&hp_sdc.rtq_lock);
 538         if (hp_sdc.rcurr >= 0) {
 539                 read_unlock_irq(&hp_sdc.rtq_lock);
 540                 goto finish;
 541         }
 542         read_unlock_irq(&hp_sdc.rtq_lock);
 543
 544
 545         if (act & HP_SDC_ACT_POSTCMD) {
 546                 uint8_t postcmd;
 547
 548                 /* curr->idx should == idx at this point. */
 549                 postcmd = curr->seq[idx];
 550                 curr->idx++;
 551                 if (act & HP_SDC_ACT_DATAIN) {
 552
 553                         /* Start a new read */
 554                         hp_sdc.rqty = curr->seq[curr->idx];
 555                         do_gettimeofday(&hp_sdc.rtv);
 556                         curr->idx++;
 557                         /* Still need to lock here in case of spurious irq. */
 558                         write_lock_irq(&hp_sdc.rtq_lock);
 559                         hp_sdc.rcurr = curridx;
 560                         write_unlock_irq(&hp_sdc.rtq_lock);
 561                         hp_sdc_status_out8(postcmd);
 562                         goto finish;
 563                 }
 564                 hp_sdc_status_out8(postcmd);
 565                 goto actdone;
 566         }
 567
 568  actdone:
 569         if (act & HP_SDC_ACT_SEMAPHORE)
 570                 up(curr->act.semaphore);
 571         else if (act & HP_SDC_ACT_CALLBACK)
 572                 curr->act.irqhook(0,NULL,0,0);
 573
 574         if (curr->idx >= curr->endidx) { /* This transaction is over. */
 575                 if (act & HP_SDC_ACT_DEALLOC)
 576                         kfree(curr);
 577                 hp_sdc.tq[curridx] = NULL;
 578         } else {
 579                 curr->actidx = idx + 1;
 580                 curr->idx = idx + 2;
 581         }
 582         /* Interleave outbound data between the transactions. */
 583         hp_sdc.wcurr++;
 584         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
 585                 hp_sdc.wcurr = 0;
 586
 587  finish:
 588         /* If by some quirk IBF has cleared and our ISR has run to
 589            see that that has happened, do it all again. */
 590         if (!hp_sdc.ibf && limit++ < 20)
 591                 goto anew;
 592
 593  done:
 594         if (hp_sdc.wcurr >= 0)
 595                 tasklet_schedule(&hp_sdc.task);
 596         write_unlock(&hp_sdc.lock);
 597
 598         return 0;
 599 }
 600
 601 /******* Functions called in either user or kernel context ****/
 602 int __hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
 603 {
 604         int i;
 605
 606         if (this == NULL) {
 607                 BUG();
 608                 return -EINVAL;
 609         }
 610
 611         /* Can't have same transaction on queue twice */
 612         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
 613                 if (hp_sdc.tq[i] == this)
 614                         goto fail;
 615
 616         this->actidx = 0;
 617         this->idx = 1;
 618
 619         /* Search for empty slot */
 620         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
 621                 if (hp_sdc.tq[i] == NULL) {
 622                         hp_sdc.tq[i] = this;
 623                         tasklet_schedule(&hp_sdc.task);
 624                         return 0;
 625                 }
 626
 627         printk(KERN_WARNING PREFIX "No free slot to add transaction.\n");
 628         return -EBUSY;
 629
 630  fail:
 631         printk(KERN_WARNING PREFIX "Transaction add failed: transaction already queued?\n");
 632         return -EINVAL;
 633 }
 634
 635 int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
 636         unsigned long flags;
 637         int ret;
 638
 639         write_lock_irqsave(&hp_sdc.lock, flags);
 640         ret = __hp_sdc_enqueue_transaction(this);
 641         write_unlock_irqrestore(&hp_sdc.lock,flags);
 642
 643         return ret;
 644 }
 645
 646 int hp_sdc_dequeue_transaction(hp_sdc_transaction *this)
 647 {
 648         unsigned long flags;
 649         int i;
 650
 651         write_lock_irqsave(&hp_sdc.lock, flags);
 652
 653         /* TODO: don't remove it if it's not done. */
 654
 655         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
 656                 if (hp_sdc.tq[i] == this)
 657                         hp_sdc.tq[i] = NULL;
 658
 659         write_unlock_irqrestore(&hp_sdc.lock, flags);
 660         return 0;
 661 }
 662
 663
 664
 665 /********************** User context functions **************************/
 666 int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback)
 667 {
 668         if (callback == NULL || hp_sdc.dev == NULL)
 669                 return -EINVAL;
 670
 671         write_lock_irq(&hp_sdc.hook_lock);
 672         if (hp_sdc.timer != NULL) {
 673                 write_unlock_irq(&hp_sdc.hook_lock);
 674                 return -EBUSY;
 675         }
 676
 677         hp_sdc.timer = callback;
 678         /* Enable interrupts from the timers */
 679         hp_sdc.im &= ~HP_SDC_IM_FH;
 680         hp_sdc.im &= ~HP_SDC_IM_PT;
 681         hp_sdc.im &= ~HP_SDC_IM_TIMERS;
 682         hp_sdc.set_im = 1;
 683         write_unlock_irq(&hp_sdc.hook_lock);
 684
 685         tasklet_schedule(&hp_sdc.task);
 686
 687         return 0;
 688 }
 689
 690 int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback)
 691 {
 692         if (callback == NULL || hp_sdc.dev == NULL)
 693                 return -EINVAL;
 694
 695         write_lock_irq(&hp_sdc.hook_lock);
 696         if (hp_sdc.hil != NULL) {
 697                 write_unlock_irq(&hp_sdc.hook_lock);
 698                 return -EBUSY;
 699         }
 700
 701         hp_sdc.hil = callback;
 702         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 703         hp_sdc.set_im = 1;
 704         write_unlock_irq(&hp_sdc.hook_lock);
 705
 706         tasklet_schedule(&hp_sdc.task);
 707
 708         return 0;
 709 }
 710
 711 int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback)
 712 {
 713         if (callback == NULL || hp_sdc.dev == NULL)
 714                 return -EINVAL;
 715
 716         write_lock_irq(&hp_sdc.hook_lock);
 717         if (hp_sdc.cooked != NULL) {
 718                 write_unlock_irq(&hp_sdc.hook_lock);
 719                 return -EBUSY;
 720         }
 721
 722         /* Enable interrupts from the HIL MLC */
 723         hp_sdc.cooked = callback;
 724         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 725         hp_sdc.set_im = 1;
 726         write_unlock_irq(&hp_sdc.hook_lock);
 727
 728         tasklet_schedule(&hp_sdc.task);
 729
 730         return 0;
 731 }
 732
 733 int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback)
 734 {
 735         write_lock_irq(&hp_sdc.hook_lock);
 736         if ((callback != hp_sdc.timer) ||
 737             (hp_sdc.timer == NULL)) {
 738                 write_unlock_irq(&hp_sdc.hook_lock);
 739                 return -EINVAL;
 740         }
 741
 742         /* Disable interrupts from the timers */
 743         hp_sdc.timer = NULL;
 744         hp_sdc.im |= HP_SDC_IM_TIMERS;
 745         hp_sdc.im |= HP_SDC_IM_FH;
 746         hp_sdc.im |= HP_SDC_IM_PT;
 747         hp_sdc.set_im = 1;
 748         write_unlock_irq(&hp_sdc.hook_lock);
 749         tasklet_schedule(&hp_sdc.task);
 750
 751         return 0;
 752 }
 753
 754 int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback)
 755 {
 756         write_lock_irq(&hp_sdc.hook_lock);
 757         if ((callback != hp_sdc.hil) ||
 758             (hp_sdc.hil == NULL)) {
 759                 write_unlock_irq(&hp_sdc.hook_lock);
 760                 return -EINVAL;
 761         }
 762
 763         hp_sdc.hil = NULL;
 764         /* Disable interrupts from HIL only if there is no cooked driver. */
 765         if(hp_sdc.cooked == NULL) {
 766                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 767                 hp_sdc.set_im = 1;
 768         }
 769         write_unlock_irq(&hp_sdc.hook_lock);
 770         tasklet_schedule(&hp_sdc.task);
 771
 772         return 0;
 773 }
 774
 775 int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback)
 776 {
 777         write_lock_irq(&hp_sdc.hook_lock);
 778         if ((callback != hp_sdc.cooked) ||
 779             (hp_sdc.cooked == NULL)) {
 780                 write_unlock_irq(&hp_sdc.hook_lock);
 781                 return -EINVAL;
 782         }
 783
 784         hp_sdc.cooked = NULL;
 785         /* Disable interrupts from HIL only if there is no raw HIL driver. */
 786         if(hp_sdc.hil == NULL) {
 787                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
 788                 hp_sdc.set_im = 1;
 789         }
 790         write_unlock_irq(&hp_sdc.hook_lock);
 791         tasklet_schedule(&hp_sdc.task);
 792
 793         return 0;
 794 }
 795
 796 /************************* Keepalive timer task *********************/
 797
 798 void hp_sdc_kicker (unsigned long data)
 799 {
 800         tasklet_schedule(&hp_sdc.task);
 801         /* Re-insert the periodic task. */
 802         mod_timer(&hp_sdc.kicker, jiffies + HZ);
 803 }
 804
 805 /************************** Module Initialization ***************************/
 806
 807 #if defined(__hppa__)
 808
 809 static const struct parisc_device_id hp_sdc_tbl[] = {
 810         {
 811                 .hw_type =      HPHW_FIO,
 812                 .hversion_rev = HVERSION_REV_ANY_ID,
 813                 .hversion =     HVERSION_ANY_ID,
 814                 .sversion =     0x73,
 815          },
 816         { 0, }
 817 };
 818
 819 MODULE_DEVICE_TABLE(parisc, hp_sdc_tbl);
 820
 821 static int __init hp_sdc_init_hppa(struct parisc_device *d);
 822
 823 static struct parisc_driver hp_sdc_driver = {
 824         .name =         "hp_sdc",
 825         .id_table =     hp_sdc_tbl,
 826         .probe =        hp_sdc_init_hppa,
 827 };
 828
 829 #endif /* __hppa__ */
 830
 831 static int __init hp_sdc_init(void)
 832 {
 833         char *errstr;
 834         hp_sdc_transaction t_sync;
 835         uint8_t ts_sync[6];
 836         struct semaphore s_sync;
 837
 838         rwlock_init(&hp_sdc.lock);
 839         rwlock_init(&hp_sdc.ibf_lock);
 840         rwlock_init(&hp_sdc.rtq_lock);
 841         rwlock_init(&hp_sdc.hook_lock);
 842
 843         hp_sdc.timer            = NULL;
 844         hp_sdc.hil              = NULL;
 845         hp_sdc.pup              = NULL;
 846         hp_sdc.cooked           = NULL;
 847         hp_sdc.im               = HP_SDC_IM_MASK;  /* Mask maskable irqs */
 848         hp_sdc.set_im           = 1;
 849         hp_sdc.wi               = 0xff;
 850         hp_sdc.r7[0]            = 0xff;
 851         hp_sdc.r7[1]            = 0xff;
 852         hp_sdc.r7[2]            = 0xff;
 853         hp_sdc.r7[3]            = 0xff;
 854         hp_sdc.ibf              = 1;
 855
 856         memset(&hp_sdc.tq, 0, sizeof(hp_sdc.tq));
 857
 858         hp_sdc.wcurr            = -1;
 859         hp_sdc.rcurr            = -1;
 860         hp_sdc.rqty             = 0;
 861
 862         hp_sdc.dev_err = -ENODEV;
 863
 864         errstr = "IO not found for";
 865         if (!hp_sdc.base_io)
 866                 goto err0;
 867
 868         errstr = "IRQ not found for";
 869         if (!hp_sdc.irq)
 870                 goto err0;
 871
 872         hp_sdc.dev_err = -EBUSY;
 873
 874 #if defined(__hppa__)
 875         errstr = "IO not available for";
 876         if (request_region(hp_sdc.data_io, 2, hp_sdc_driver.name))
 877                 goto err0;
 878 #endif
 879
 880         errstr = "IRQ not available for";
 881         if (request_irq(hp_sdc.irq, &hp_sdc_isr, IRQF_SHARED|IRQF_SAMPLE_RANDOM,
 882                         "HP SDC", &hp_sdc))
 883                 goto err1;
 884
 885         errstr = "NMI not available for";
 886         if (request_irq(hp_sdc.nmi, &hp_sdc_nmisr, IRQF_SHARED,
 887                         "HP SDC NMI", &hp_sdc))
 888                 goto err2;
 889
 890         printk(KERN_INFO PREFIX "HP SDC at 0x%p, IRQ %d (NMI IRQ %d)\n",
 891                (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
 892
 893         hp_sdc_status_in8();
 894         hp_sdc_data_in8();
 895
 896         tasklet_init(&hp_sdc.task, hp_sdc_tasklet, 0);
 897
 898         /* Sync the output buffer registers, thus scheduling hp_sdc_tasklet. */
 899         t_sync.actidx   = 0;
 900         t_sync.idx      = 1;
 901         t_sync.endidx   = 6;
 902         t_sync.seq      = ts_sync;
 903         ts_sync[0]      = HP_SDC_ACT_DATAREG | HP_SDC_ACT_SEMAPHORE;
 904         ts_sync[1]      = 0x0f;
 905         ts_sync[2] = ts_sync[3] = ts_sync[4] = ts_sync[5] = 0;
 906         t_sync.act.semaphore = &s_sync;
 907         init_MUTEX_LOCKED(&s_sync);
 908         hp_sdc_enqueue_transaction(&t_sync);
 909         down(&s_sync); /* Wait for t_sync to complete */
 910
 911         /* Create the keepalive task */
 912         init_timer(&hp_sdc.kicker);
 913         hp_sdc.kicker.expires = jiffies + HZ;
 914         hp_sdc.kicker.function = &hp_sdc_kicker;
 915         add_timer(&hp_sdc.kicker);
 916
 917         hp_sdc.dev_err = 0;
 918         return 0;
 919  err2:
 920         free_irq(hp_sdc.irq, &hp_sdc);
 921  err1:
 922         release_region(hp_sdc.data_io, 2);
 923  err0:
 924         printk(KERN_WARNING PREFIX ": %s SDC IO=0x%p IRQ=0x%x NMI=0x%x\n",
 925                 errstr, (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
 926         hp_sdc.dev = NULL;
 927
 928         return hp_sdc.dev_err;
 929 }
 930
 931 #if defined(__hppa__)
 932
 933 static int __init hp_sdc_init_hppa(struct parisc_device *d)
 934 {
 935         if (!d)
 936                 return 1;
 937         if (hp_sdc.dev != NULL)
 938                 return 1;       /* We only expect one SDC */
 939
 940         hp_sdc.dev              = d;
 941         hp_sdc.irq              = d->irq;
 942         hp_sdc.nmi              = d->aux_irq;
 943         hp_sdc.base_io          = d->hpa.start;
 944         hp_sdc.data_io          = d->hpa.start + 0x800;
 945         hp_sdc.status_io        = d->hpa.start + 0x801;
 946
 947         return hp_sdc_init();
 948 }
 949
 950 #endif /* __hppa__ */
 951
 952 static void hp_sdc_exit(void)
 953 {
 954         write_lock_irq(&hp_sdc.lock);
 955
 956         /* Turn off all maskable "sub-function" irq's. */
 957         hp_sdc_spin_ibf();
 958         sdc_writeb(HP_SDC_CMD_SET_IM | HP_SDC_IM_MASK, hp_sdc.status_io);
 959
 960         /* Wait until we know this has been processed by the i8042 */
 961         hp_sdc_spin_ibf();
 962
 963         free_irq(hp_sdc.nmi, &hp_sdc);
 964         free_irq(hp_sdc.irq, &hp_sdc);
 965         write_unlock_irq(&hp_sdc.lock);
 966
 967         del_timer(&hp_sdc.kicker);
 968
 969         tasklet_kill(&hp_sdc.task);
 970
 971 #if defined(__hppa__)
 972         if (unregister_parisc_driver(&hp_sdc_driver))
 973                 printk(KERN_WARNING PREFIX "Error unregistering HP SDC");
 974 #endif
 975 }
 976
 977 static int __init hp_sdc_register(void)
 978 {
 979         hp_sdc_transaction tq_init;
 980         uint8_t tq_init_seq[5];
 981         struct semaphore tq_init_sem;
 982 #if defined(__mc68000__)
 983         mm_segment_t fs;
 984         unsigned char i;
 985 #endif
 986
 987         if (hp_sdc_disabled) {
 988                 printk(KERN_WARNING PREFIX "HP SDC driver disabled by no_hpsdc=1.\n");
 989                 return -ENODEV;
 990         }
 991
 992         hp_sdc.dev = NULL;
 993         hp_sdc.dev_err = 0;
 994 #if defined(__hppa__)
 995         if (register_parisc_driver(&hp_sdc_driver)) {
 996                 printk(KERN_WARNING PREFIX "Error registering SDC with system bus tree.\n");
 997                 return -ENODEV;
 998         }
 999 #elif defined(__mc68000__)
1000         if (!MACH_IS_HP300)
1001             return -ENODEV;
1002
1003         hp_sdc.irq       = 1;
1004         hp_sdc.nmi       = 7;
1005         hp_sdc.base_io   = (unsigned long) 0xf0428000;
1006         hp_sdc.data_io   = (unsigned long) hp_sdc.base_io + 1;
1007         hp_sdc.status_io = (unsigned long) hp_sdc.base_io + 3;
1008         fs = get_fs();
1009         set_fs(KERNEL_DS);
1010         if (!get_user(i, (unsigned char *)hp_sdc.data_io))
1011                 hp_sdc.dev = (void *)1;
1012         set_fs(fs);
1013         hp_sdc.dev_err   = hp_sdc_init();
1014 #endif
1015         if (hp_sdc.dev == NULL) {
1016                 printk(KERN_WARNING PREFIX "No SDC found.\n");
1017                 return hp_sdc.dev_err;
1018         }
1019
1020         init_MUTEX_LOCKED(&tq_init_sem);
1021
1022         tq_init.actidx          = 0;
1023         tq_init.idx             = 1;
1024         tq_init.endidx          = 5;
1025         tq_init.seq             = tq_init_seq;
1026         tq_init.act.semaphore   = &tq_init_sem;
1027
1028         tq_init_seq[0] =
1029                 HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
1030         tq_init_seq[1] = HP_SDC_CMD_READ_KCC;
1031         tq_init_seq[2] = 1;
1032         tq_init_seq[3] = 0;
1033         tq_init_seq[4] = 0;
1034
1035         hp_sdc_enqueue_transaction(&tq_init);
1036
1037         down(&tq_init_sem);
1038         up(&tq_init_sem);
1039
1040         if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
1041                 printk(KERN_WARNING PREFIX "Error reading config byte.\n");
1042                 hp_sdc_exit();
1043                 return -ENODEV;
1044         }
1045         hp_sdc.r11 = tq_init_seq[4];
1046         if (hp_sdc.r11 & HP_SDC_CFG_NEW) {
1047                 const char *str;
1048                 printk(KERN_INFO PREFIX "New style SDC\n");
1049                 tq_init_seq[1] = HP_SDC_CMD_READ_XTD;
1050                 tq_init.actidx          = 0;
1051                 tq_init.idx             = 1;
1052                 down(&tq_init_sem);
1053                 hp_sdc_enqueue_transaction(&tq_init);
1054                 down(&tq_init_sem);
1055                 up(&tq_init_sem);
1056                 if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
1057                         printk(KERN_WARNING PREFIX "Error reading extended config byte.\n");
1058                         return -ENODEV;
1059                 }
1060                 hp_sdc.r7e = tq_init_seq[4];
1061                 HP_SDC_XTD_REV_STRINGS(hp_sdc.r7e & HP_SDC_XTD_REV, str)
1062                 printk(KERN_INFO PREFIX "Revision: %s\n", str);
1063                 if (hp_sdc.r7e & HP_SDC_XTD_BEEPER)
1064                         printk(KERN_INFO PREFIX "TI SN76494 beeper present\n");
1065                 if (hp_sdc.r7e & HP_SDC_XTD_BBRTC)
1066                         printk(KERN_INFO PREFIX "OKI MSM-58321 BBRTC present\n");
1067                 printk(KERN_INFO PREFIX "Spunking the self test register to force PUP "
1068                        "on next firmware reset.\n");
1069                 tq_init_seq[0] = HP_SDC_ACT_PRECMD |
1070                         HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
1071                 tq_init_seq[1] = HP_SDC_CMD_SET_STR;
1072                 tq_init_seq[2] = 1;
1073                 tq_init_seq[3] = 0;
1074                 tq_init.actidx          = 0;
1075                 tq_init.idx             = 1;
1076                 tq_init.endidx          = 4;
1077                 down(&tq_init_sem);
1078                 hp_sdc_enqueue_transaction(&tq_init);
1079                 down(&tq_init_sem);
1080                 up(&tq_init_sem);
1081         } else
1082                 printk(KERN_INFO PREFIX "Old style SDC (1820-%s).\n",
1083                        (hp_sdc.r11 & HP_SDC_CFG_REV) ? "3300" : "2564/3087");
1084
1085         return 0;
1086 }
1087
1088 module_init(hp_sdc_register);
1089 module_exit(hp_sdc_exit);
1090
1091 /* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64)
1092  *                                              cycles cycles-adj    time
1093  * between two consecutive mfctl(16)'s:              4        n/a    63ns
1094  * hp_sdc_spin_ibf when idle:                      119        115   1.7us
1095  * gsc_writeb status register:                      83         79   1.2us
1096  * IBF to clear after sending SET_IM:             6204       6006    93us
1097  * IBF to clear after sending LOAD_RT:            4467       4352    68us
1098  * IBF to clear after sending two LOAD_RTs:      18974      18859   295us
1099  * READ_T1, read status/data, IRQ, call handler: 35564        n/a   556us
1100  * cmd to ~IBF READ_T1 2nd time right after:   5158403        n/a    81ms
1101  * between IRQ received and ~IBF for above:    2578877        n/a    40ms
1102  *
1103  * Performance stats after a run of this module configuring HIL and
1104  * receiving a few mouse events:
1105  *
1106  * status in8  282508 cycles 7128 calls
1107  * status out8   8404 cycles  341 calls
1108  * data out8     1734 cycles   78 calls
1109  * isr         174324 cycles  617 calls (includes take)
1110  * take          1241 cycles    2 calls
1111  * put        1411504 cycles 6937 calls
1112  * task       1655209 cycles 6937 calls (includes put)
1113  *
1114  */