drivers/macintosh/via-cuda.c

   1 /*
   2  * Device driver for the via-cuda on Apple Powermacs.
   3  *
   4  * The VIA (versatile interface adapter) interfaces to the CUDA,
   5  * a 6805 microprocessor core which controls the ADB (Apple Desktop
   6  * Bus) which connects to the keyboard and mouse.  The CUDA also
   7  * controls system power and the RTC (real time clock) chip.
   8  *
   9  * Copyright (C) 1996 Paul Mackerras.
  10  */
  11 #include <stdarg.h>
  12 #include <linux/types.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/delay.h>
  16 #include <linux/adb.h>
  17 #include <linux/cuda.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/interrupt.h>
  20 #ifdef CONFIG_PPC
  21 #include <asm/prom.h>
  22 #include <asm/machdep.h>
  23 #else
  24 #include <asm/macintosh.h>
  25 #include <asm/macints.h>
  26 #include <asm/mac_via.h>
  27 #endif
  28 #include <asm/io.h>
  29 #include <linux/init.h>
  30
  31 static volatile unsigned char __iomem *via;
  32 static DEFINE_SPINLOCK(cuda_lock);
  33
  34 /* VIA registers - spaced 0x200 bytes apart */
  35 #define RS              0x200           /* skip between registers */
  36 #define B               0               /* B-side data */
  37 #define A               RS              /* A-side data */
  38 #define DIRB            (2*RS)          /* B-side direction (1=output) */
  39 #define DIRA            (3*RS)          /* A-side direction (1=output) */
  40 #define T1CL            (4*RS)          /* Timer 1 ctr/latch (low 8 bits) */
  41 #define T1CH            (5*RS)          /* Timer 1 counter (high 8 bits) */
  42 #define T1LL            (6*RS)          /* Timer 1 latch (low 8 bits) */
  43 #define T1LH            (7*RS)          /* Timer 1 latch (high 8 bits) */
  44 #define T2CL            (8*RS)          /* Timer 2 ctr/latch (low 8 bits) */
  45 #define T2CH            (9*RS)          /* Timer 2 counter (high 8 bits) */
  46 #define SR              (10*RS)         /* Shift register */
  47 #define ACR             (11*RS)         /* Auxiliary control register */
  48 #define PCR             (12*RS)         /* Peripheral control register */
  49 #define IFR             (13*RS)         /* Interrupt flag register */
  50 #define IER             (14*RS)         /* Interrupt enable register */
  51 #define ANH             (15*RS)         /* A-side data, no handshake */
  52
  53 /* Bits in B data register: all active low */
  54 #define TREQ            0x08            /* Transfer request (input) */
  55 #define TACK            0x10            /* Transfer acknowledge (output) */
  56 #define TIP             0x20            /* Transfer in progress (output) */
  57
  58 /* Bits in ACR */
  59 #define SR_CTRL         0x1c            /* Shift register control bits */
  60 #define SR_EXT          0x0c            /* Shift on external clock */
  61 #define SR_OUT          0x10            /* Shift out if 1 */
  62
  63 /* Bits in IFR and IER */
  64 #define IER_SET         0x80            /* set bits in IER */
  65 #define IER_CLR         0               /* clear bits in IER */
  66 #define SR_INT          0x04            /* Shift register full/empty */
  67
  68 static enum cuda_state {
  69     idle,
  70     sent_first_byte,
  71     sending,
  72     reading,
  73     read_done,
  74     awaiting_reply
  75 } cuda_state;
  76
  77 static struct adb_request *current_req;
  78 static struct adb_request *last_req;
  79 static unsigned char cuda_rbuf[16];
  80 static unsigned char *reply_ptr;
  81 static int reading_reply;
  82 static int data_index;
  83 static int cuda_irq;
  84 #ifdef CONFIG_PPC
  85 static struct device_node *vias;
  86 #endif
  87 static int cuda_fully_inited;
  88
  89 #ifdef CONFIG_ADB
  90 static int cuda_probe(void);
  91 static int cuda_send_request(struct adb_request *req, int sync);
  92 static int cuda_adb_autopoll(int devs);
  93 static int cuda_reset_adb_bus(void);
  94 #endif /* CONFIG_ADB */
  95
  96 static int cuda_init_via(void);
  97 static void cuda_start(void);
  98 static irqreturn_t cuda_interrupt(int irq, void *arg);
  99 static void cuda_input(unsigned char *buf, int nb);
 100 void cuda_poll(void);
 101 static int cuda_write(struct adb_request *req);
 102
 103 int cuda_request(struct adb_request *req,
 104                  void (*done)(struct adb_request *), int nbytes, ...);
 105
 106 #ifdef CONFIG_ADB
 107 struct adb_driver via_cuda_driver = {
 108         .name         = "CUDA",
 109         .probe        = cuda_probe,
 110         .send_request = cuda_send_request,
 111         .autopoll     = cuda_adb_autopoll,
 112         .poll         = cuda_poll,
 113         .reset_bus    = cuda_reset_adb_bus,
 114 };
 115 #endif /* CONFIG_ADB */
 116
 117 #ifdef CONFIG_MAC
 118 int __init find_via_cuda(void)
 119 {
 120     struct adb_request req;
 121     int err;
 122
 123     if (macintosh_config->adb_type != MAC_ADB_CUDA)
 124         return 0;
 125
 126     via = via1;
 127     cuda_state = idle;
 128
 129     err = cuda_init_via();
 130     if (err) {
 131         printk(KERN_ERR "cuda_init_via() failed\n");
 132         via = NULL;
 133         return 0;
 134     }
 135
 136     /* enable autopoll */
 137     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
 138     while (!req.complete)
 139         cuda_poll();
 140
 141     return 1;
 142 }
 143 #else
 144 int __init find_via_cuda(void)
 145 {
 146     struct adb_request req;
 147     phys_addr_t taddr;
 148     const u32 *reg;
 149     int err;
 150
 151     if (vias != 0)
 152         return 1;
 153     vias = of_find_node_by_name(NULL, "via-cuda");
 154     if (vias == 0)
 155         return 0;
 156
 157     reg = of_get_property(vias, "reg", NULL);
 158     if (reg == NULL) {
 159             printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
 160             goto fail;
 161     }
 162     taddr = of_translate_address(vias, reg);
 163     if (taddr == 0) {
 164             printk(KERN_ERR "via-cuda: Can't translate address !\n");
 165             goto fail;
 166     }
 167     via = ioremap(taddr, 0x2000);
 168     if (via == NULL) {
 169             printk(KERN_ERR "via-cuda: Can't map address !\n");
 170             goto fail;
 171     }
 172
 173     cuda_state = idle;
 174     sys_ctrler = SYS_CTRLER_CUDA;
 175
 176     err = cuda_init_via();
 177     if (err) {
 178         printk(KERN_ERR "cuda_init_via() failed\n");
 179         via = NULL;
 180         return 0;
 181     }
 182
 183     /* Clear and enable interrupts, but only on PPC. On 68K it's done  */
 184     /* for us by the main VIA driver in arch/m68k/mac/via.c        */
 185
 186     out_8(&via[IFR], 0x7f);     /* clear interrupts by writing 1s */
 187     out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
 188
 189     /* enable autopoll */
 190     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
 191     while (!req.complete)
 192         cuda_poll();
 193
 194     return 1;
 195
 196  fail:
 197     of_node_put(vias);
 198     vias = NULL;
 199     return 0;
 200 }
 201 #endif /* !defined CONFIG_MAC */
 202
 203 static int __init via_cuda_start(void)
 204 {
 205     if (via == NULL)
 206         return -ENODEV;
 207
 208 #ifdef CONFIG_MAC
 209     cuda_irq = IRQ_MAC_ADB;
 210 #else
 211     cuda_irq = irq_of_parse_and_map(vias, 0);
 212     if (cuda_irq == NO_IRQ) {
 213         printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
 214                vias->full_name);
 215         return -ENODEV;
 216     }
 217 #endif
 218
 219     if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
 220         printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
 221         return -EAGAIN;
 222     }
 223
 224     printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
 225
 226     cuda_fully_inited = 1;
 227     return 0;
 228 }
 229
 230 device_initcall(via_cuda_start);
 231
 232 #ifdef CONFIG_ADB
 233 static int
 234 cuda_probe(void)
 235 {
 236 #ifdef CONFIG_PPC
 237     if (sys_ctrler != SYS_CTRLER_CUDA)
 238         return -ENODEV;
 239 #else
 240     if (macintosh_config->adb_type != MAC_ADB_CUDA)
 241         return -ENODEV;
 242 #endif
 243     if (via == NULL)
 244         return -ENODEV;
 245     return 0;
 246 }
 247 #endif /* CONFIG_ADB */
 248
 249 #define WAIT_FOR(cond, what)                                    \
 250     do {                                                        \
 251         int x;                                                  \
 252         for (x = 1000; !(cond); --x) {                          \
 253             if (x == 0) {                                       \
 254                 printk("Timeout waiting for " what "\n");       \
 255                 return -ENXIO;                                  \
 256             }                                                   \
 257             udelay(100);                                        \
 258         }                                                       \
 259     } while (0)
 260
 261 static int
 262 cuda_init_via(void)
 263 {
 264     out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
 265     out_8(&via[B], in_8(&via[B]) | TACK | TIP);                 /* negate them */
 266     out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT);    /* SR data in */
 267     (void)in_8(&via[SR]);                                               /* clear any left-over data */
 268 #ifdef CONFIG_PPC
 269     out_8(&via[IER], 0x7f);                                     /* disable interrupts from VIA */
 270     (void)in_8(&via[IER]);
 271 #else
 272     out_8(&via[IER], SR_INT);                                   /* disable SR interrupt from VIA */
 273 #endif
 274
 275     /* delay 4ms and then clear any pending interrupt */
 276     mdelay(4);
 277     (void)in_8(&via[SR]);
 278     out_8(&via[IFR], SR_INT);
 279
 280     /* sync with the CUDA - assert TACK without TIP */
 281     out_8(&via[B], in_8(&via[B]) & ~TACK);
 282
 283     /* wait for the CUDA to assert TREQ in response */
 284     WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
 285
 286     /* wait for the interrupt and then clear it */
 287     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
 288     (void)in_8(&via[SR]);
 289     out_8(&via[IFR], SR_INT);
 290
 291     /* finish the sync by negating TACK */
 292     out_8(&via[B], in_8(&via[B]) | TACK);
 293
 294     /* wait for the CUDA to negate TREQ and the corresponding interrupt */
 295     WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
 296     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
 297     (void)in_8(&via[SR]);
 298     out_8(&via[IFR], SR_INT);
 299     out_8(&via[B], in_8(&via[B]) | TIP);        /* should be unnecessary */
 300
 301     return 0;
 302 }
 303
 304 #ifdef CONFIG_ADB
 305 /* Send an ADB command */
 306 static int
 307 cuda_send_request(struct adb_request *req, int sync)
 308 {
 309     int i;
 310
 311     if ((via == NULL) || !cuda_fully_inited) {
 312         req->complete = 1;
 313         return -ENXIO;
 314     }
 315
 316     req->reply_expected = 1;
 317
 318     i = cuda_write(req);
 319     if (i)
 320         return i;
 321
 322     if (sync) {
 323         while (!req->complete)
 324             cuda_poll();
 325     }
 326     return 0;
 327 }
 328
 329
 330 /* Enable/disable autopolling */
 331 static int
 332 cuda_adb_autopoll(int devs)
 333 {
 334     struct adb_request req;
 335
 336     if ((via == NULL) || !cuda_fully_inited)
 337         return -ENXIO;
 338
 339     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
 340     while (!req.complete)
 341         cuda_poll();
 342     return 0;
 343 }
 344
 345 /* Reset adb bus - how do we do this?? */
 346 static int
 347 cuda_reset_adb_bus(void)
 348 {
 349     struct adb_request req;
 350
 351     if ((via == NULL) || !cuda_fully_inited)
 352         return -ENXIO;
 353
 354     cuda_request(&req, NULL, 2, ADB_PACKET, 0);         /* maybe? */
 355     while (!req.complete)
 356         cuda_poll();
 357     return 0;
 358 }
 359 #endif /* CONFIG_ADB */
 360 /* Construct and send a cuda request */
 361 int
 362 cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
 363              int nbytes, ...)
 364 {
 365     va_list list;
 366     int i;
 367
 368     if (via == NULL) {
 369         req->complete = 1;
 370         return -ENXIO;
 371     }
 372
 373     req->nbytes = nbytes;
 374     req->done = done;
 375     va_start(list, nbytes);
 376     for (i = 0; i < nbytes; ++i)
 377         req->data[i] = va_arg(list, int);
 378     va_end(list);
 379     req->reply_expected = 1;
 380     return cuda_write(req);
 381 }
 382
 383 static int
 384 cuda_write(struct adb_request *req)
 385 {
 386     unsigned long flags;
 387
 388     if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
 389         req->complete = 1;
 390         return -EINVAL;
 391     }
 392     req->next = NULL;
 393     req->sent = 0;
 394     req->complete = 0;
 395     req->reply_len = 0;
 396
 397     spin_lock_irqsave(&cuda_lock, flags);
 398     if (current_req != 0) {
 399         last_req->next = req;
 400         last_req = req;
 401     } else {
 402         current_req = req;
 403         last_req = req;
 404         if (cuda_state == idle)
 405             cuda_start();
 406     }
 407     spin_unlock_irqrestore(&cuda_lock, flags);
 408
 409     return 0;
 410 }
 411
 412 static void
 413 cuda_start(void)
 414 {
 415     struct adb_request *req;
 416
 417     /* assert cuda_state == idle */
 418     /* get the packet to send */
 419     req = current_req;
 420     if (req == 0)
 421         return;
 422     if ((in_8(&via[B]) & TREQ) == 0)
 423         return;                 /* a byte is coming in from the CUDA */
 424
 425     /* set the shift register to shift out and send a byte */
 426     out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
 427     out_8(&via[SR], req->data[0]);
 428     out_8(&via[B], in_8(&via[B]) & ~TIP);
 429     cuda_state = sent_first_byte;
 430 }
 431
 432 void
 433 cuda_poll(void)
 434 {
 435     /* cuda_interrupt only takes a normal lock, we disable
 436      * interrupts here to avoid re-entering and thus deadlocking.
 437      */
 438     if (cuda_irq)
 439         disable_irq(cuda_irq);
 440     cuda_interrupt(0, NULL);
 441     if (cuda_irq)
 442         enable_irq(cuda_irq);
 443 }
 444
 445 static irqreturn_t
 446 cuda_interrupt(int irq, void *arg)
 447 {
 448     int status;
 449     struct adb_request *req = NULL;
 450     unsigned char ibuf[16];
 451     int ibuf_len = 0;
 452     int complete = 0;
 453
 454     spin_lock(&cuda_lock);
 455
 456     /* On powermacs, this handler is registered for the VIA IRQ. But they use
 457      * just the shift register IRQ -- other VIA interrupt sources are disabled.
 458      * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
 459      * we are polling, the shift register IRQ flag has already been cleared.
 460      */
 461
 462 #ifdef CONFIG_MAC
 463     if (!arg)
 464 #endif
 465     {
 466         if ((in_8(&via[IFR]) & SR_INT) == 0) {
 467             spin_unlock(&cuda_lock);
 468             return IRQ_NONE;
 469         } else {
 470             out_8(&via[IFR], SR_INT);
 471         }
 472     }
 473
 474     status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
 475     /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
 476     switch (cuda_state) {
 477     case idle:
 478         /* CUDA has sent us the first byte of data - unsolicited */
 479         if (status != TREQ)
 480             printk("cuda: state=idle, status=%x\n", status);
 481         (void)in_8(&via[SR]);
 482         out_8(&via[B], in_8(&via[B]) & ~TIP);
 483         cuda_state = reading;
 484         reply_ptr = cuda_rbuf;
 485         reading_reply = 0;
 486         break;
 487
 488     case awaiting_reply:
 489         /* CUDA has sent us the first byte of data of a reply */
 490         if (status != TREQ)
 491             printk("cuda: state=awaiting_reply, status=%x\n", status);
 492         (void)in_8(&via[SR]);
 493         out_8(&via[B], in_8(&via[B]) & ~TIP);
 494         cuda_state = reading;
 495         reply_ptr = current_req->reply;
 496         reading_reply = 1;
 497         break;
 498
 499     case sent_first_byte:
 500         if (status == TREQ + TIP + SR_OUT) {
 501             /* collision */
 502             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 503             (void)in_8(&via[SR]);
 504             out_8(&via[B], in_8(&via[B]) | TIP | TACK);
 505             cuda_state = idle;
 506         } else {
 507             /* assert status == TIP + SR_OUT */
 508             if (status != TIP + SR_OUT)
 509                 printk("cuda: state=sent_first_byte status=%x\n", status);
 510             out_8(&via[SR], current_req->data[1]);
 511             out_8(&via[B], in_8(&via[B]) ^ TACK);
 512             data_index = 2;
 513             cuda_state = sending;
 514         }
 515         break;
 516
 517     case sending:
 518         req = current_req;
 519         if (data_index >= req->nbytes) {
 520             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 521             (void)in_8(&via[SR]);
 522             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 523             req->sent = 1;
 524             if (req->reply_expected) {
 525                 cuda_state = awaiting_reply;
 526             } else {
 527                 current_req = req->next;
 528                 complete = 1;
 529                 /* not sure about this */
 530                 cuda_state = idle;
 531                 cuda_start();
 532             }
 533         } else {
 534             out_8(&via[SR], req->data[data_index++]);
 535             out_8(&via[B], in_8(&via[B]) ^ TACK);
 536         }
 537         break;
 538
 539     case reading:
 540         *reply_ptr++ = in_8(&via[SR]);
 541         if (status == TIP) {
 542             /* that's all folks */
 543             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 544             cuda_state = read_done;
 545         } else {
 546             /* assert status == TIP | TREQ */
 547             if (status != TIP + TREQ)
 548                 printk("cuda: state=reading status=%x\n", status);
 549             out_8(&via[B], in_8(&via[B]) ^ TACK);
 550         }
 551         break;
 552
 553     case read_done:
 554         (void)in_8(&via[SR]);
 555         if (reading_reply) {
 556             req = current_req;
 557             req->reply_len = reply_ptr - req->reply;
 558             if (req->data[0] == ADB_PACKET) {
 559                 /* Have to adjust the reply from ADB commands */
 560                 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
 561                     /* the 0x2 bit indicates no response */
 562                     req->reply_len = 0;
 563                 } else {
 564                     /* leave just the command and result bytes in the reply */
 565                     req->reply_len -= 2;
 566                     memmove(req->reply, req->reply + 2, req->reply_len);
 567                 }
 568             }
 569             current_req = req->next;
 570             complete = 1;
 571         } else {
 572             /* This is tricky. We must break the spinlock to call
 573              * cuda_input. However, doing so means we might get
 574              * re-entered from another CPU getting an interrupt
 575              * or calling cuda_poll(). I ended up using the stack
 576              * (it's only for 16 bytes) and moving the actual
 577              * call to cuda_input to outside of the lock.
 578              */
 579             ibuf_len = reply_ptr - cuda_rbuf;
 580             memcpy(ibuf, cuda_rbuf, ibuf_len);
 581         }
 582         if (status == TREQ) {
 583             out_8(&via[B], in_8(&via[B]) & ~TIP);
 584             cuda_state = reading;
 585             reply_ptr = cuda_rbuf;
 586             reading_reply = 0;
 587         } else {
 588             cuda_state = idle;
 589             cuda_start();
 590         }
 591         break;
 592
 593     default:
 594         printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
 595     }
 596     spin_unlock(&cuda_lock);
 597     if (complete && req) {
 598         void (*done)(struct adb_request *) = req->done;
 599         mb();
 600         req->complete = 1;
 601         /* Here, we assume that if the request has a done member, the
 602          * struct request will survive to setting req->complete to 1
 603          */
 604         if (done)
 605                 (*done)(req);
 606     }
 607     if (ibuf_len)
 608         cuda_input(ibuf, ibuf_len);
 609     return IRQ_HANDLED;
 610 }
 611
 612 static void
 613 cuda_input(unsigned char *buf, int nb)
 614 {
 615     int i;
 616
 617     switch (buf[0]) {
 618     case ADB_PACKET:
 619 #ifdef CONFIG_XMON
 620         if (nb == 5 && buf[2] == 0x2c) {
 621             extern int xmon_wants_key, xmon_adb_keycode;
 622             if (xmon_wants_key) {
 623                 xmon_adb_keycode = buf[3];
 624                 return;
 625             }
 626         }
 627 #endif /* CONFIG_XMON */
 628 #ifdef CONFIG_ADB
 629         adb_input(buf+2, nb-2, buf[1] & 0x40);
 630 #endif /* CONFIG_ADB */
 631         break;
 632
 633     default:
 634         printk("data from cuda (%d bytes):", nb);
 635         for (i = 0; i < nb; ++i)
 636             printk(" %.2x", buf[i]);
 637         printk("\n");
 638     }
 639 }