drivers/macintosh/via-maciisi.c

   1 /*
   2  * Device driver for the IIsi-style ADB on some Mac LC and II-class machines
   3  *
   4  * Based on via-cuda.c and via-macii.c, as well as the original
   5  * adb-bus.c, which in turn is somewhat influenced by (but uses no
   6  * code from) the NetBSD HWDIRECT ADB code.  Original IIsi driver work
   7  * was done by Robert Thompson and integrated into the old style
   8  * driver by Michael Schmitz.
   9  *
  10  * Original sources (c) Alan Cox, Paul Mackerras, and others.
  11  *
  12  * Rewritten for Unified ADB by David Huggins-Daines <dhd@debian.org>
  13  *
  14  * 7/13/2000- extensive changes by Andrew McPherson <andrew@macduff.dhs.org>
  15  * Works about 30% of the time now.
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/errno.h>
  20 #include <linux/kernel.h>
  21 #include <linux/adb.h>
  22 #include <linux/cuda.h>
  23 #include <linux/delay.h>
  24 #include <linux/interrupt.h>
  25 #include <asm/macintosh.h>
  26 #include <asm/macints.h>
  27 #include <asm/mac_via.h>
  28
  29 static volatile unsigned char *via;
  30
  31 /* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
  32 #define RS              0x200           /* skip between registers */
  33 #define B               0               /* B-side data */
  34 #define A               RS              /* A-side data */
  35 #define DIRB            (2*RS)          /* B-side direction (1=output) */
  36 #define DIRA            (3*RS)          /* A-side direction (1=output) */
  37 #define SR              (10*RS)         /* Shift register */
  38 #define ACR             (11*RS)         /* Auxiliary control register */
  39 #define IFR             (13*RS)         /* Interrupt flag register */
  40 #define IER             (14*RS)         /* Interrupt enable register */
  41
  42 /* Bits in B data register: all active low */
  43 #define TREQ            0x08            /* Transfer request (input) */
  44 #define TACK            0x10            /* Transfer acknowledge (output) */
  45 #define TIP             0x20            /* Transfer in progress (output) */
  46 #define ST_MASK         0x30            /* mask for selecting ADB state bits */
  47
  48 /* Bits in ACR */
  49 #define SR_CTRL         0x1c            /* Shift register control bits */
  50 #define SR_EXT          0x0c            /* Shift on external clock */
  51 #define SR_OUT          0x10            /* Shift out if 1 */
  52
  53 /* Bits in IFR and IER */
  54 #define IER_SET         0x80            /* set bits in IER */
  55 #define IER_CLR         0               /* clear bits in IER */
  56 #define SR_INT          0x04            /* Shift register full/empty */
  57 #define SR_DATA         0x08            /* Shift register data */
  58 #define SR_CLOCK        0x10            /* Shift register clock */
  59
  60 #define ADB_DELAY 150
  61
  62 #undef DEBUG_MACIISI_ADB
  63
  64 static struct adb_request* current_req;
  65 static struct adb_request* last_req;
  66 static unsigned char maciisi_rbuf[16];
  67 static unsigned char *reply_ptr;
  68 static int data_index;
  69 static int reading_reply;
  70 static int reply_len;
  71 static int tmp;
  72 static int need_sync;
  73
  74 static enum maciisi_state {
  75     idle,
  76     sending,
  77     reading,
  78 } maciisi_state;
  79
  80 static int maciisi_probe(void);
  81 static int maciisi_init(void);
  82 static int maciisi_send_request(struct adb_request* req, int sync);
  83 static void maciisi_sync(struct adb_request *req);
  84 static int maciisi_write(struct adb_request* req);
  85 static irqreturn_t maciisi_interrupt(int irq, void* arg);
  86 static void maciisi_input(unsigned char *buf, int nb);
  87 static int maciisi_init_via(void);
  88 static void maciisi_poll(void);
  89 static int maciisi_start(void);
  90
  91 struct adb_driver via_maciisi_driver = {
  92         "Mac IIsi",
  93         maciisi_probe,
  94         maciisi_init,
  95         maciisi_send_request,
  96         NULL, /* maciisi_adb_autopoll, */
  97         maciisi_poll,
  98         NULL /* maciisi_reset_adb_bus */
  99 };
 100
 101 static int
 102 maciisi_probe(void)
 103 {
 104         if (macintosh_config->adb_type != MAC_ADB_IISI)
 105                 return -ENODEV;
 106
 107         via = via1;
 108         return 0;
 109 }
 110
 111 static int
 112 maciisi_init(void)
 113 {
 114         int err;
 115
 116         if (via == NULL)
 117                 return -ENODEV;
 118
 119         if ((err = maciisi_init_via())) {
 120                 printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
 121                 via = NULL;
 122                 return err;
 123         }
 124
 125         if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK | IRQ_FLG_FAST,
 126                         "ADB", maciisi_interrupt)) {
 127                 printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
 128                 return -EAGAIN;
 129         }
 130
 131         printk("adb: Mac IIsi driver v0.2 for Unified ADB.\n");
 132         return 0;
 133 }
 134
 135 /* Flush data from the ADB controller */
 136 static void
 137 maciisi_stfu(void)
 138 {
 139         int status = via[B] & (TIP|TREQ);
 140
 141         if (status & TREQ) {
 142 #ifdef DEBUG_MACIISI_ADB
 143                 printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
 144 #endif
 145                 return;
 146         }
 147
 148         udelay(ADB_DELAY);
 149         via[ACR] &= ~SR_OUT;
 150         via[IER] = IER_CLR | SR_INT;
 151
 152         udelay(ADB_DELAY);
 153
 154         status = via[B] & (TIP|TREQ);
 155
 156         if (!(status & TREQ))
 157         {
 158                 via[B] |= TIP;
 159
 160                 while(1)
 161                 {
 162                         int poll_timeout = ADB_DELAY * 5;
 163                         /* Poll for SR interrupt */
 164                         while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
 165                                 status = via[B] & (TIP|TREQ);
 166
 167                         tmp = via[SR]; /* Clear shift register */
 168 #ifdef DEBUG_MACIISI_ADB
 169                         printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d data %x\n",
 170                                status, poll_timeout, tmp);
 171 #endif
 172                         if(via[B] & TREQ)
 173                                 break;
 174
 175                         /* ACK on-off */
 176                         via[B] |= TACK;
 177                         udelay(ADB_DELAY);
 178                         via[B] &= ~TACK;
 179                 }
 180
 181                 /* end frame */
 182                 via[B] &= ~TIP;
 183                 udelay(ADB_DELAY);
 184         }
 185
 186         via[IER] = IER_SET | SR_INT;
 187 }
 188
 189 /* All specifically VIA-related initialization goes here */
 190 static int
 191 maciisi_init_via(void)
 192 {
 193         int     i;
 194
 195         /* Set the lines up. We want TREQ as input TACK|TIP as output */
 196         via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
 197         /* Shift register on input */
 198         via[ACR]  = (via[ACR] & ~SR_CTRL) | SR_EXT;
 199 #ifdef DEBUG_MACIISI_ADB
 200         printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
 201 #endif
 202         /* Wipe any pending data and int */
 203         tmp = via[SR];
 204         /* Enable keyboard interrupts */
 205         via[IER] = IER_SET | SR_INT;
 206         /* Set initial state: idle */
 207         via[B] &= ~(TACK|TIP);
 208         /* Clear interrupt bit */
 209         via[IFR] = SR_INT;
 210
 211         for(i = 0; i < 60; i++) {
 212                 udelay(ADB_DELAY);
 213                 maciisi_stfu();
 214                 udelay(ADB_DELAY);
 215                 if(via[B] & TREQ)
 216                         break;
 217         }
 218         if (i == 60)
 219                 printk(KERN_ERR "maciisi_init_via: bus jam?\n");
 220
 221         maciisi_state = idle;
 222         need_sync = 0;
 223
 224         return 0;
 225 }
 226
 227 /* Send a request, possibly waiting for a reply */
 228 static int
 229 maciisi_send_request(struct adb_request* req, int sync)
 230 {
 231         int i;
 232
 233 #ifdef DEBUG_MACIISI_ADB
 234         static int dump_packet = 0;
 235 #endif
 236
 237         if (via == NULL) {
 238                 req->complete = 1;
 239                 return -ENXIO;
 240         }
 241
 242 #ifdef DEBUG_MACIISI_ADB
 243         if (dump_packet) {
 244                 printk(KERN_DEBUG "maciisi_send_request:");
 245                 for (i = 0; i < req->nbytes; i++) {
 246                         printk(" %.2x", req->data[i]);
 247                 }
 248                 printk(" sync %d\n", sync);
 249         }
 250 #endif
 251
 252         req->reply_expected = 1;
 253
 254         i = maciisi_write(req);
 255         if (i)
 256         {
 257                 /* Normally, if a packet requires syncing, that happens at the end of
 258                  * maciisi_send_request. But if the transfer fails, it will be restarted
 259                  * by maciisi_interrupt(). We use need_sync to tell maciisi_interrupt
 260                  * when to sync a packet that it sends out.
 261                  *
 262                  * Suggestions on a better way to do this are welcome.
 263                  */
 264                 if(i == -EBUSY && sync)
 265                         need_sync = 1;
 266                 else
 267                         need_sync = 0;
 268                 return i;
 269         }
 270         if(sync)
 271                 maciisi_sync(req);
 272
 273         return 0;
 274 }
 275
 276 /* Poll the ADB chip until the request completes */
 277 static void maciisi_sync(struct adb_request *req)
 278 {
 279         int count = 0;
 280
 281 #ifdef DEBUG_MACIISI_ADB
 282         printk(KERN_DEBUG "maciisi_sync called\n");
 283 #endif
 284
 285         /* If for some reason the ADB chip shuts up on us, we want to avoid an endless loop. */
 286         while (!req->complete && count++ < 50) {
 287                 maciisi_poll();
 288         }
 289         /* This could be BAD... when the ADB controller doesn't respond
 290          * for this long, it's probably not coming back :-( */
 291         if (count > 50) /* Hopefully shouldn't happen */
 292                 printk(KERN_ERR "maciisi_send_request: poll timed out!\n");
 293 }
 294
 295 int
 296 maciisi_request(struct adb_request *req, void (*done)(struct adb_request *),
 297             int nbytes, ...)
 298 {
 299         va_list list;
 300         int i;
 301
 302         req->nbytes = nbytes;
 303         req->done = done;
 304         req->reply_expected = 0;
 305         va_start(list, nbytes);
 306         for (i = 0; i < nbytes; i++)
 307                 req->data[i++] = va_arg(list, int);
 308         va_end(list);
 309
 310         return maciisi_send_request(req, 1);
 311 }
 312
 313 /* Enqueue a request, and run the queue if possible */
 314 static int
 315 maciisi_write(struct adb_request* req)
 316 {
 317         unsigned long flags;
 318         int i;
 319
 320         /* We will accept CUDA packets - the VIA sends them to us, so
 321            it figures that we should be able to send them to it */
 322         if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
 323                 printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
 324                 req->complete = 1;
 325                 return -EINVAL;
 326         }
 327         req->next = NULL;
 328         req->sent = 0;
 329         req->complete = 0;
 330         req->reply_len = 0;
 331
 332         local_irq_save(flags);
 333
 334         if (current_req) {
 335                 last_req->next = req;
 336                 last_req = req;
 337         } else {
 338                 current_req = req;
 339                 last_req = req;
 340         }
 341         if (maciisi_state == idle)
 342         {
 343                 i = maciisi_start();
 344                 if(i != 0)
 345                 {
 346                         local_irq_restore(flags);
 347                         return i;
 348                 }
 349         }
 350         else
 351         {
 352 #ifdef DEBUG_MACIISI_ADB
 353                 printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
 354 #endif
 355                 local_irq_restore(flags);
 356                 return -EBUSY;
 357         }
 358
 359         local_irq_restore(flags);
 360
 361         return 0;
 362 }
 363
 364 static int
 365 maciisi_start(void)
 366 {
 367         struct adb_request* req;
 368         int status;
 369
 370 #ifdef DEBUG_MACIISI_ADB
 371         status = via[B] & (TIP | TREQ);
 372
 373         printk(KERN_DEBUG "maciisi_start called, state=%d, status=%x, ifr=%x\n", maciisi_state, status, via[IFR]);
 374 #endif
 375
 376         if (maciisi_state != idle) {
 377                 /* shouldn't happen */
 378                 printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
 379                 return -EBUSY;
 380         }
 381
 382         req = current_req;
 383         if (req == NULL)
 384                 return -EINVAL;
 385
 386         status = via[B] & (TIP|TREQ);
 387         if (!(status & TREQ)) {
 388 #ifdef DEBUG_MACIISI_ADB
 389                 printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
 390 #endif
 391                 return -EBUSY;
 392         }
 393
 394         /* Okay, send */
 395 #ifdef DEBUG_MACIISI_ADB
 396         printk(KERN_DEBUG "maciisi_start: sending\n");
 397 #endif
 398         /* Set state to active */
 399         via[B] |= TIP;
 400         /* ACK off */
 401         via[B] &= ~TACK;
 402         /* Delay */
 403         udelay(ADB_DELAY);
 404         /* Shift out and send */
 405         via[ACR] |= SR_OUT;
 406         via[SR] = req->data[0];
 407         data_index = 1;
 408         /* ACK on */
 409         via[B] |= TACK;
 410         maciisi_state = sending;
 411
 412         return 0;
 413 }
 414
 415 void
 416 maciisi_poll(void)
 417 {
 418         unsigned long flags;
 419
 420         local_irq_save(flags);
 421         if (via[IFR] & SR_INT) {
 422                 maciisi_interrupt(0, NULL);
 423         }
 424         else /* avoid calling this function too quickly in a loop */
 425                 udelay(ADB_DELAY);
 426
 427         local_irq_restore(flags);
 428 }
 429
 430 /* Shift register interrupt - this is *supposed* to mean that the
 431    register is either full or empty. In practice, I have no idea what
 432    it means :( */
 433 static irqreturn_t
 434 maciisi_interrupt(int irq, void* arg)
 435 {
 436         int status;
 437         struct adb_request *req;
 438 #ifdef DEBUG_MACIISI_ADB
 439         static int dump_reply = 0;
 440 #endif
 441         int i;
 442         unsigned long flags;
 443
 444         local_irq_save(flags);
 445
 446         status = via[B] & (TIP|TREQ);
 447 #ifdef DEBUG_MACIISI_ADB
 448         printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
 449 #endif
 450
 451         if (!(via[IFR] & SR_INT)) {
 452                 /* Shouldn't happen, we hope */
 453                 printk(KERN_ERR "maciisi_interrupt: called without interrupt flag set\n");
 454                 local_irq_restore(flags);
 455                 return IRQ_NONE;
 456         }
 457
 458         /* Clear the interrupt */
 459         /* via[IFR] = SR_INT; */
 460
 461  switch_start:
 462         switch (maciisi_state) {
 463         case idle:
 464                 if (status & TIP)
 465                         printk(KERN_ERR "maciisi_interrupt: state is idle but TIP asserted!\n");
 466
 467                 if(!reading_reply)
 468                         udelay(ADB_DELAY);
 469                 /* Shift in */
 470                 via[ACR] &= ~SR_OUT;
 471                 /* Signal start of frame */
 472                 via[B] |= TIP;
 473                 /* Clear the interrupt (throw this value on the floor, it's useless) */
 474                 tmp = via[SR];
 475                 /* ACK adb chip, high-low */
 476                 via[B] |= TACK;
 477                 udelay(ADB_DELAY);
 478                 via[B] &= ~TACK;
 479                 reply_len = 0;
 480                 maciisi_state = reading;
 481                 if (reading_reply) {
 482                         reply_ptr = current_req->reply;
 483                 } else {
 484                         reply_ptr = maciisi_rbuf;
 485                 }
 486                 break;
 487
 488         case sending:
 489                 /* via[SR]; */
 490                 /* Set ACK off */
 491                 via[B] &= ~TACK;
 492                 req = current_req;
 493
 494                 if (!(status & TREQ)) {
 495                         /* collision */
 496                         printk(KERN_ERR "maciisi_interrupt: send collision\n");
 497                         /* Set idle and input */
 498                         via[ACR] &= ~SR_OUT;
 499                         tmp = via[SR];
 500                         via[B] &= ~TIP;
 501                         /* Must re-send */
 502                         reading_reply = 0;
 503                         reply_len = 0;
 504                         maciisi_state = idle;
 505                         udelay(ADB_DELAY);
 506                         /* process this now, because the IFR has been cleared */
 507                         goto switch_start;
 508                 }
 509
 510                 udelay(ADB_DELAY);
 511
 512                 if (data_index >= req->nbytes) {
 513                         /* Sent the whole packet, put the bus back in idle state */
 514                         /* Shift in, we are about to read a reply (hopefully) */
 515                         via[ACR] &= ~SR_OUT;
 516                         tmp = via[SR];
 517                         /* End of frame */
 518                         via[B] &= ~TIP;
 519                         req->sent = 1;
 520                         maciisi_state = idle;
 521                         if (req->reply_expected) {
 522                                 /* Note: only set this once we've
 523                                    successfully sent the packet */
 524                                 reading_reply = 1;
 525                         } else {
 526                                 current_req = req->next;
 527                                 if (req->done)
 528                                         (*req->done)(req);
 529                                 /* Do any queued requests now */
 530                                 i = maciisi_start();
 531                                 if(i == 0 && need_sync) {
 532                                         /* Packet needs to be synced */
 533                                         maciisi_sync(current_req);
 534                                 }
 535                                 if(i != -EBUSY)
 536                                         need_sync = 0;
 537                         }
 538                 } else {
 539                         /* Sending more stuff */
 540                         /* Shift out */
 541                         via[ACR] |= SR_OUT;
 542                         /* Write */
 543                         via[SR] = req->data[data_index++];
 544                         /* Signal 'byte ready' */
 545                         via[B] |= TACK;
 546                 }
 547                 break;
 548
 549         case reading:
 550                 /* Shift in */
 551                 /* via[ACR] &= ~SR_OUT; */ /* Not in 2.2 */
 552                 if (reply_len++ > 16) {
 553                         printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
 554                         via[B] |= TACK;
 555                         udelay(ADB_DELAY);
 556                         via[B] &= ~(TACK|TIP);
 557                         maciisi_state = idle;
 558                         i = maciisi_start();
 559                         if(i == 0 && need_sync) {
 560                                 /* Packet needs to be synced */
 561                                 maciisi_sync(current_req);
 562                         }
 563                         if(i != -EBUSY)
 564                                 need_sync = 0;
 565                         break;
 566                 }
 567                 /* Read data */
 568                 *reply_ptr++ = via[SR];
 569                 status = via[B] & (TIP|TREQ);
 570                 /* ACK on/off */
 571                 via[B] |= TACK;
 572                 udelay(ADB_DELAY);
 573                 via[B] &= ~TACK;
 574                 if (!(status & TREQ))
 575                         break; /* more stuff to deal with */
 576
 577                 /* end of frame */
 578                 via[B] &= ~TIP;
 579                 tmp = via[SR]; /* That's what happens in 2.2 */
 580                 udelay(ADB_DELAY); /* Give controller time to recover */
 581
 582                 /* end of packet, deal with it */
 583                 if (reading_reply) {
 584                         req = current_req;
 585                         req->reply_len = reply_ptr - req->reply;
 586                         if (req->data[0] == ADB_PACKET) {
 587                                 /* Have to adjust the reply from ADB commands */
 588                                 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
 589                                         /* the 0x2 bit indicates no response */
 590                                         req->reply_len = 0;
 591                                 } else {
 592                                         /* leave just the command and result bytes in the reply */
 593                                         req->reply_len -= 2;
 594                                         memmove(req->reply, req->reply + 2, req->reply_len);
 595                                 }
 596                         }
 597 #ifdef DEBUG_MACIISI_ADB
 598                         if (dump_reply) {
 599                                 int i;
 600                                 printk(KERN_DEBUG "maciisi_interrupt: reply is ");
 601                                 for (i = 0; i < req->reply_len; ++i)
 602                                         printk(" %.2x", req->reply[i]);
 603                                 printk("\n");
 604                         }
 605 #endif
 606                         req->complete = 1;
 607                         current_req = req->next;
 608                         if (req->done)
 609                                 (*req->done)(req);
 610                         /* Obviously, we got it */
 611                         reading_reply = 0;
 612                 } else {
 613                         maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf);
 614                 }
 615                 maciisi_state = idle;
 616                 status = via[B] & (TIP|TREQ);
 617                 if (!(status & TREQ)) {
 618                         /* Timeout?! More likely, another packet coming in already */
 619 #ifdef DEBUG_MACIISI_ADB
 620                         printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
 621                                status, via[IFR]);
 622 #endif
 623 #if 0
 624                         udelay(ADB_DELAY);
 625                         via[B] |= TIP;
 626
 627                         maciisi_state = reading;
 628                         reading_reply = 0;
 629                         reply_ptr = maciisi_rbuf;
 630 #else
 631                         /* Process the packet now */
 632                         reading_reply = 0;
 633                         goto switch_start;
 634 #endif
 635                         /* We used to do this... but the controller might actually have data for us */
 636                         /* maciisi_stfu(); */
 637                 }
 638                 else {
 639                         /* Do any queued requests now if possible */
 640                         i = maciisi_start();
 641                         if(i == 0 && need_sync) {
 642                                 /* Packet needs to be synced */
 643                                 maciisi_sync(current_req);
 644                         }
 645                         if(i != -EBUSY)
 646                                 need_sync = 0;
 647                 }
 648                 break;
 649
 650         default:
 651                 printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
 652         }
 653         local_irq_restore(flags);
 654         return IRQ_HANDLED;
 655 }
 656
 657 static void
 658 maciisi_input(unsigned char *buf, int nb)
 659 {
 660 #ifdef DEBUG_MACIISI_ADB
 661     int i;
 662 #endif
 663
 664     switch (buf[0]) {
 665     case ADB_PACKET:
 666             adb_input(buf+2, nb-2, buf[1] & 0x40);
 667             break;
 668     default:
 669 #ifdef DEBUG_MACIISI_ADB
 670             printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
 671             for (i = 0; i < nb; ++i)
 672                     printk(" %.2x", buf[i]);
 673             printk("\n");
 674 #endif
 675             break;
 676     }
 677 }