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