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/machw.h>
  28 #include <asm/mac_via.h>
  29
  30 static volatile unsigned char *via;
  31
  32 /* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
  33 #define RS              0x200           /* skip between registers */
  34 #define B               0               /* B-side data */
  35 #define A               RS              /* A-side data */
  36 #define DIRB            (2*RS)          /* B-side direction (1=output) */
  37 #define DIRA            (3*RS)          /* A-side direction (1=output) */
  38 #define SR              (10*RS)         /* Shift register */
  39 #define ACR             (11*RS)         /* Auxiliary control register */
  40 #define IFR             (13*RS)         /* Interrupt flag register */
  41 #define IER             (14*RS)         /* Interrupt enable register */
  42
  43 /* Bits in B data register: all active low */
  44 #define TREQ            0x08            /* Transfer request (input) */
  45 #define TACK            0x10            /* Transfer acknowledge (output) */
  46 #define TIP             0x20            /* Transfer in progress (output) */
  47 #define ST_MASK         0x30            /* mask for selecting ADB state bits */
  48
  49 /* Bits in ACR */
  50 #define SR_CTRL         0x1c            /* Shift register control bits */
  51 #define SR_EXT          0x0c            /* Shift on external clock */
  52 #define SR_OUT          0x10            /* Shift out if 1 */
  53
  54 /* Bits in IFR and IER */
  55 #define IER_SET         0x80            /* set bits in IER */
  56 #define IER_CLR         0               /* clear bits in IER */
  57 #define SR_INT          0x04            /* Shift register full/empty */
  58 #define SR_DATA         0x08            /* Shift register data */
  59 #define SR_CLOCK        0x10            /* Shift register clock */
  60
  61 #define ADB_DELAY 150
  62
  63 #undef DEBUG_MACIISI_ADB
  64
  65 static struct adb_request* current_req;
  66 static struct adb_request* last_req;
  67 static unsigned char maciisi_rbuf[16];
  68 static unsigned char *reply_ptr;
  69 static int data_index;
  70 static int reading_reply;
  71 static int reply_len;
  72 static int tmp;
  73 static int need_sync;
  74
  75 static enum maciisi_state {
  76     idle,
  77     sending,
  78     reading,
  79 } maciisi_state;
  80
  81 static int maciisi_probe(void);
  82 static int maciisi_init(void);
  83 static int maciisi_send_request(struct adb_request* req, int sync);
  84 static void maciisi_sync(struct adb_request *req);
  85 static int maciisi_write(struct adb_request* req);
  86 static irqreturn_t maciisi_interrupt(int irq, void* arg);
  87 static void maciisi_input(unsigned char *buf, int nb);
  88 static int maciisi_init_via(void);
  89 static void maciisi_poll(void);
  90 static int maciisi_start(void);
  91
  92 struct adb_driver via_maciisi_driver = {
  93         "Mac IIsi",
  94         maciisi_probe,
  95         maciisi_init,
  96         maciisi_send_request,
  97         NULL, /* maciisi_adb_autopoll, */
  98         maciisi_poll,
  99         NULL /* maciisi_reset_adb_bus */
 100 };
 101
 102 static int
 103 maciisi_probe(void)
 104 {
 105         if (macintosh_config->adb_type != MAC_ADB_IISI)
 106                 return -ENODEV;
 107
 108         via = via1;
 109         return 0;
 110 }
 111
 112 static int
 113 maciisi_init(void)
 114 {
 115         int err;
 116
 117         if (via == NULL)
 118                 return -ENODEV;
 119
 120         if ((err = maciisi_init_via())) {
 121                 printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
 122                 via = NULL;
 123                 return err;
 124         }
 125
 126         if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK | IRQ_FLG_FAST,
 127                         "ADB", maciisi_interrupt)) {
 128                 printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
 129                 return -EAGAIN;
 130         }
 131
 132         printk("adb: Mac IIsi driver v0.2 for Unified ADB.\n");
 133         return 0;
 134 }
 135
 136 /* Flush data from the ADB controller */
 137 static void
 138 maciisi_stfu(void)
 139 {
 140         int status = via[B] & (TIP|TREQ);
 141
 142         if (status & TREQ) {
 143 #ifdef DEBUG_MACIISI_ADB
 144                 printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
 145 #endif
 146                 return;
 147         }
 148
 149         udelay(ADB_DELAY);
 150         via[ACR] &= ~SR_OUT;
 151         via[IER] = IER_CLR | SR_INT;
 152
 153         udelay(ADB_DELAY);
 154
 155         status = via[B] & (TIP|TREQ);
 156
 157         if (!(status & TREQ))
 158         {
 159                 via[B] |= TIP;
 160
 161                 while(1)
 162                 {
 163                         int poll_timeout = ADB_DELAY * 5;
 164                         /* Poll for SR interrupt */
 165                         while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
 166                                 status = via[B] & (TIP|TREQ);
 167
 168                         tmp = via[SR]; /* Clear shift register */
 169 #ifdef DEBUG_MACIISI_ADB
 170                         printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d data %x\n",
 171                                status, poll_timeout, tmp);
 172 #endif
 173                         if(via[B] & TREQ)
 174                                 break;
 175
 176                         /* ACK on-off */
 177                         via[B] |= TACK;
 178                         udelay(ADB_DELAY);
 179                         via[B] &= ~TACK;
 180                 }
 181
 182                 /* end frame */
 183                 via[B] &= ~TIP;
 184                 udelay(ADB_DELAY);
 185         }
 186
 187         via[IER] = IER_SET | SR_INT;
 188 }
 189
 190 /* All specifically VIA-related initialization goes here */
 191 static int
 192 maciisi_init_via(void)
 193 {
 194         int     i;
 195
 196         /* Set the lines up. We want TREQ as input TACK|TIP as output */
 197         via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
 198         /* Shift register on input */
 199         via[ACR]  = (via[ACR] & ~SR_CTRL) | SR_EXT;
 200 #ifdef DEBUG_MACIISI_ADB
 201         printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
 202 #endif
 203         /* Wipe any pending data and int */
 204         tmp = via[SR];
 205         /* Enable keyboard interrupts */
 206         via[IER] = IER_SET | SR_INT;
 207         /* Set initial state: idle */
 208         via[B] &= ~(TACK|TIP);
 209         /* Clear interrupt bit */
 210         via[IFR] = SR_INT;
 211
 212         for(i = 0; i < 60; i++) {
 213                 udelay(ADB_DELAY);
 214                 maciisi_stfu();
 215                 udelay(ADB_DELAY);
 216                 if(via[B] & TREQ)
 217                         break;
 218         }
 219         if (i == 60)
 220                 printk(KERN_ERR "maciisi_init_via: bus jam?\n");
 221
 222         maciisi_state = idle;
 223         need_sync = 0;
 224
 225         return 0;
 226 }
 227
 228 /* Send a request, possibly waiting for a reply */
 229 static int
 230 maciisi_send_request(struct adb_request* req, int sync)
 231 {
 232         int i;
 233
 234 #ifdef DEBUG_MACIISI_ADB
 235         static int dump_packet = 0;
 236 #endif
 237
 238         if (via == NULL) {
 239                 req->complete = 1;
 240                 return -ENXIO;
 241         }
 242
 243 #ifdef DEBUG_MACIISI_ADB
 244         if (dump_packet) {
 245                 printk(KERN_DEBUG "maciisi_send_request:");
 246                 for (i = 0; i < req->nbytes; i++) {
 247                         printk(" %.2x", req->data[i]);
 248                 }
 249                 printk(" sync %d\n", sync);
 250         }
 251 #endif
 252
 253         req->reply_expected = 1;
 254
 255         i = maciisi_write(req);
 256         if (i)
 257         {
 258                 /* Normally, if a packet requires syncing, that happens at the end of
 259                  * maciisi_send_request. But if the transfer fails, it will be restarted
 260                  * by maciisi_interrupt(). We use need_sync to tell maciisi_interrupt
 261                  * when to sync a packet that it sends out.
 262                  *
 263                  * Suggestions on a better way to do this are welcome.
 264                  */
 265                 if(i == -EBUSY && sync)
 266                         need_sync = 1;
 267                 else
 268                         need_sync = 0;
 269                 return i;
 270         }
 271         if(sync)
 272                 maciisi_sync(req);
 273
 274         return 0;
 275 }
 276
 277 /* Poll the ADB chip until the request completes */
 278 static void maciisi_sync(struct adb_request *req)
 279 {
 280         int count = 0;
 281
 282 #ifdef DEBUG_MACIISI_ADB
 283         printk(KERN_DEBUG "maciisi_sync called\n");
 284 #endif
 285
 286         /* If for some reason the ADB chip shuts up on us, we want to avoid an endless loop. */
 287         while (!req->complete && count++ < 50) {
 288                 maciisi_poll();
 289         }
 290         /* This could be BAD... when the ADB controller doesn't respond
 291          * for this long, it's probably not coming back :-( */
 292         if(count >= 50) /* Hopefully shouldn't happen */
 293                 printk(KERN_ERR "maciisi_send_request: poll timed out!\n");
 294 }
 295
 296 int
 297 maciisi_request(struct adb_request *req, void (*done)(struct adb_request *),
 298             int nbytes, ...)
 299 {
 300         va_list list;
 301         int i;
 302
 303         req->nbytes = nbytes;
 304         req->done = done;
 305         req->reply_expected = 0;
 306         va_start(list, nbytes);
 307         for (i = 0; i < nbytes; i++)
 308                 req->data[i++] = va_arg(list, int);
 309         va_end(list);
 310
 311         return maciisi_send_request(req, 1);
 312 }
 313
 314 /* Enqueue a request, and run the queue if possible */
 315 static int
 316 maciisi_write(struct adb_request* req)
 317 {
 318         unsigned long flags;
 319         int i;
 320
 321         /* We will accept CUDA packets - the VIA sends them to us, so
 322            it figures that we should be able to send them to it */
 323         if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
 324                 printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
 325                 req->complete = 1;
 326                 return -EINVAL;
 327         }
 328         req->next = NULL;
 329         req->sent = 0;
 330         req->complete = 0;
 331         req->reply_len = 0;
 332
 333         local_irq_save(flags);
 334
 335         if (current_req) {
 336                 last_req->next = req;
 337                 last_req = req;
 338         } else {
 339                 current_req = req;
 340                 last_req = req;
 341         }
 342         if (maciisi_state == idle)
 343         {
 344                 i = maciisi_start();
 345                 if(i != 0)
 346                 {
 347                         local_irq_restore(flags);
 348                         return i;
 349                 }
 350         }
 351         else
 352         {
 353 #ifdef DEBUG_MACIISI_ADB
 354                 printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
 355 #endif
 356                 local_irq_restore(flags);
 357                 return -EBUSY;
 358         }
 359
 360         local_irq_restore(flags);
 361
 362         return 0;
 363 }
 364
 365 static int
 366 maciisi_start(void)
 367 {
 368         struct adb_request* req;
 369         int status;
 370
 371 #ifdef DEBUG_MACIISI_ADB
 372         status = via[B] & (TIP | TREQ);
 373
 374         printk(KERN_DEBUG "maciisi_start called, state=%d, status=%x, ifr=%x\n", maciisi_state, status, via[IFR]);
 375 #endif
 376
 377         if (maciisi_state != idle) {
 378                 /* shouldn't happen */
 379                 printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
 380                 return -EBUSY;
 381         }
 382
 383         req = current_req;
 384         if (req == NULL)
 385                 return -EINVAL;
 386
 387         status = via[B] & (TIP|TREQ);
 388         if (!(status & TREQ)) {
 389 #ifdef DEBUG_MACIISI_ADB
 390                 printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
 391 #endif
 392                 return -EBUSY;
 393         }
 394
 395         /* Okay, send */
 396 #ifdef DEBUG_MACIISI_ADB
 397         printk(KERN_DEBUG "maciisi_start: sending\n");
 398 #endif
 399         /* Set state to active */
 400         via[B] |= TIP;
 401         /* ACK off */
 402         via[B] &= ~TACK;
 403         /* Delay */
 404         udelay(ADB_DELAY);
 405         /* Shift out and send */
 406         via[ACR] |= SR_OUT;
 407         via[SR] = req->data[0];
 408         data_index = 1;
 409         /* ACK on */
 410         via[B] |= TACK;
 411         maciisi_state = sending;
 412
 413         return 0;
 414 }
 415
 416 void
 417 maciisi_poll(void)
 418 {
 419         unsigned long flags;
 420
 421         local_irq_save(flags);
 422         if (via[IFR] & SR_INT) {
 423                 maciisi_interrupt(0, NULL);
 424         }
 425         else /* avoid calling this function too quickly in a loop */
 426                 udelay(ADB_DELAY);
 427
 428         local_irq_restore(flags);
 429 }
 430
 431 /* Shift register interrupt - this is *supposed* to mean that the
 432    register is either full or empty. In practice, I have no idea what
 433    it means :( */
 434 static irqreturn_t
 435 maciisi_interrupt(int irq, void* arg)
 436 {
 437         int status;
 438         struct adb_request *req;
 439 #ifdef DEBUG_MACIISI_ADB
 440         static int dump_reply = 0;
 441 #endif
 442         int i;
 443         unsigned long flags;
 444
 445         local_irq_save(flags);
 446
 447         status = via[B] & (TIP|TREQ);
 448 #ifdef DEBUG_MACIISI_ADB
 449         printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
 450 #endif
 451
 452         if (!(via[IFR] & SR_INT)) {
 453                 /* Shouldn't happen, we hope */
 454                 printk(KERN_ERR "maciisi_interrupt: called without interrupt flag set\n");
 455                 local_irq_restore(flags);
 456                 return IRQ_NONE;
 457         }
 458
 459         /* Clear the interrupt */
 460         /* via[IFR] = SR_INT; */
 461
 462  switch_start:
 463         switch (maciisi_state) {
 464         case idle:
 465                 if (status & TIP)
 466                         printk(KERN_ERR "maciisi_interrupt: state is idle but TIP asserted!\n");
 467
 468                 if(!reading_reply)
 469                         udelay(ADB_DELAY);
 470                 /* Shift in */
 471                 via[ACR] &= ~SR_OUT;
 472                 /* Signal start of frame */
 473                 via[B] |= TIP;
 474                 /* Clear the interrupt (throw this value on the floor, it's useless) */
 475                 tmp = via[SR];
 476                 /* ACK adb chip, high-low */
 477                 via[B] |= TACK;
 478                 udelay(ADB_DELAY);
 479                 via[B] &= ~TACK;
 480                 reply_len = 0;
 481                 maciisi_state = reading;
 482                 if (reading_reply) {
 483                         reply_ptr = current_req->reply;
 484                 } else {
 485                         reply_ptr = maciisi_rbuf;
 486                 }
 487                 break;
 488
 489         case sending:
 490                 /* via[SR]; */
 491                 /* Set ACK off */
 492                 via[B] &= ~TACK;
 493                 req = current_req;
 494
 495                 if (!(status & TREQ)) {
 496                         /* collision */
 497                         printk(KERN_ERR "maciisi_interrupt: send collision\n");
 498                         /* Set idle and input */
 499                         via[ACR] &= ~SR_OUT;
 500                         tmp = via[SR];
 501                         via[B] &= ~TIP;
 502                         /* Must re-send */
 503                         reading_reply = 0;
 504                         reply_len = 0;
 505                         maciisi_state = idle;
 506                         udelay(ADB_DELAY);
 507                         /* process this now, because the IFR has been cleared */
 508                         goto switch_start;
 509                 }
 510
 511                 udelay(ADB_DELAY);
 512
 513                 if (data_index >= req->nbytes) {
 514                         /* Sent the whole packet, put the bus back in idle state */
 515                         /* Shift in, we are about to read a reply (hopefully) */
 516                         via[ACR] &= ~SR_OUT;
 517                         tmp = via[SR];
 518                         /* End of frame */
 519                         via[B] &= ~TIP;
 520                         req->sent = 1;
 521                         maciisi_state = idle;
 522                         if (req->reply_expected) {
 523                                 /* Note: only set this once we've
 524                                    successfully sent the packet */
 525                                 reading_reply = 1;
 526                         } else {
 527                                 current_req = req->next;
 528                                 if (req->done)
 529                                         (*req->done)(req);
 530                                 /* Do any queued requests now */
 531                                 i = maciisi_start();
 532                                 if(i == 0 && need_sync) {
 533                                         /* Packet needs to be synced */
 534                                         maciisi_sync(current_req);
 535                                 }
 536                                 if(i != -EBUSY)
 537                                         need_sync = 0;
 538                         }
 539                 } else {
 540                         /* Sending more stuff */
 541                         /* Shift out */
 542                         via[ACR] |= SR_OUT;
 543                         /* Write */
 544                         via[SR] = req->data[data_index++];
 545                         /* Signal 'byte ready' */
 546                         via[B] |= TACK;
 547                 }
 548                 break;
 549
 550         case reading:
 551                 /* Shift in */
 552                 /* via[ACR] &= ~SR_OUT; */ /* Not in 2.2 */
 553                 if (reply_len++ > 16) {
 554                         printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
 555                         via[B] |= TACK;
 556                         udelay(ADB_DELAY);
 557                         via[B] &= ~(TACK|TIP);
 558                         maciisi_state = idle;
 559                         i = maciisi_start();
 560                         if(i == 0 && need_sync) {
 561                                 /* Packet needs to be synced */
 562                                 maciisi_sync(current_req);
 563                         }
 564                         if(i != -EBUSY)
 565                                 need_sync = 0;
 566                         break;
 567                 }
 568                 /* Read data */
 569                 *reply_ptr++ = via[SR];
 570                 status = via[B] & (TIP|TREQ);
 571                 /* ACK on/off */
 572                 via[B] |= TACK;
 573                 udelay(ADB_DELAY);
 574                 via[B] &= ~TACK;
 575                 if (!(status & TREQ))
 576                         break; /* more stuff to deal with */
 577
 578                 /* end of frame */
 579                 via[B] &= ~TIP;
 580                 tmp = via[SR]; /* That's what happens in 2.2 */
 581                 udelay(ADB_DELAY); /* Give controller time to recover */
 582
 583                 /* end of packet, deal with it */
 584                 if (reading_reply) {
 585                         req = current_req;
 586                         req->reply_len = reply_ptr - req->reply;
 587                         if (req->data[0] == ADB_PACKET) {
 588                                 /* Have to adjust the reply from ADB commands */
 589                                 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
 590                                         /* the 0x2 bit indicates no response */
 591                                         req->reply_len = 0;
 592                                 } else {
 593                                         /* leave just the command and result bytes in the reply */
 594                                         req->reply_len -= 2;
 595                                         memmove(req->reply, req->reply + 2, req->reply_len);
 596                                 }
 597                         }
 598 #ifdef DEBUG_MACIISI_ADB
 599                         if (dump_reply) {
 600                                 int i;
 601                                 printk(KERN_DEBUG "maciisi_interrupt: reply is ");
 602                                 for (i = 0; i < req->reply_len; ++i)
 603                                         printk(" %.2x", req->reply[i]);
 604                                 printk("\n");
 605                         }
 606 #endif
 607                         req->complete = 1;
 608                         current_req = req->next;
 609                         if (req->done)
 610                                 (*req->done)(req);
 611                         /* Obviously, we got it */
 612                         reading_reply = 0;
 613                 } else {
 614                         maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf);
 615                 }
 616                 maciisi_state = idle;
 617                 status = via[B] & (TIP|TREQ);
 618                 if (!(status & TREQ)) {
 619                         /* Timeout?! More likely, another packet coming in already */
 620 #ifdef DEBUG_MACIISI_ADB
 621                         printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
 622                                status, via[IFR]);
 623 #endif
 624 #if 0
 625                         udelay(ADB_DELAY);
 626                         via[B] |= TIP;
 627
 628                         maciisi_state = reading;
 629                         reading_reply = 0;
 630                         reply_ptr = maciisi_rbuf;
 631 #else
 632                         /* Process the packet now */
 633                         reading_reply = 0;
 634                         goto switch_start;
 635 #endif
 636                         /* We used to do this... but the controller might actually have data for us */
 637                         /* maciisi_stfu(); */
 638                 }
 639                 else {
 640                         /* Do any queued requests now if possible */
 641                         i = maciisi_start();
 642                         if(i == 0 && need_sync) {
 643                                 /* Packet needs to be synced */
 644                                 maciisi_sync(current_req);
 645                         }
 646                         if(i != -EBUSY)
 647                                 need_sync = 0;
 648                 }
 649                 break;
 650
 651         default:
 652                 printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
 653         }
 654         local_irq_restore(flags);
 655         return IRQ_HANDLED;
 656 }
 657
 658 static void
 659 maciisi_input(unsigned char *buf, int nb)
 660 {
 661 #ifdef DEBUG_MACIISI_ADB
 662     int i;
 663 #endif
 664
 665     switch (buf[0]) {
 666     case ADB_PACKET:
 667             adb_input(buf+2, nb-2, buf[1] & 0x40);
 668             break;
 669     default:
 670 #ifdef DEBUG_MACIISI_ADB
 671             printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
 672             for (i = 0; i < nb; ++i)
 673                     printk(" %.2x", buf[i]);
 674             printk("\n");
 675 #endif
 676             break;
 677     }
 678 }