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) {
 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 __init 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 EXPORT_SYMBOL(cuda_request);
 383
 384 static int
 385 cuda_write(struct adb_request *req)
 386 {
 387     unsigned long flags;
 388
 389     if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
 390         req->complete = 1;
 391         return -EINVAL;
 392     }
 393     req->next = NULL;
 394     req->sent = 0;
 395     req->complete = 0;
 396     req->reply_len = 0;
 397
 398     spin_lock_irqsave(&cuda_lock, flags);
 399     if (current_req != 0) {
 400         last_req->next = req;
 401         last_req = req;
 402     } else {
 403         current_req = req;
 404         last_req = req;
 405         if (cuda_state == idle)
 406             cuda_start();
 407     }
 408     spin_unlock_irqrestore(&cuda_lock, flags);
 409
 410     return 0;
 411 }
 412
 413 static void
 414 cuda_start(void)
 415 {
 416     struct adb_request *req;
 417
 418     /* assert cuda_state == idle */
 419     /* get the packet to send */
 420     req = current_req;
 421     if (req == 0)
 422         return;
 423     if ((in_8(&via[B]) & TREQ) == 0)
 424         return;                 /* a byte is coming in from the CUDA */
 425
 426     /* set the shift register to shift out and send a byte */
 427     out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
 428     out_8(&via[SR], req->data[0]);
 429     out_8(&via[B], in_8(&via[B]) & ~TIP);
 430     cuda_state = sent_first_byte;
 431 }
 432
 433 void
 434 cuda_poll(void)
 435 {
 436     /* cuda_interrupt only takes a normal lock, we disable
 437      * interrupts here to avoid re-entering and thus deadlocking.
 438      */
 439     if (cuda_irq)
 440         disable_irq(cuda_irq);
 441     cuda_interrupt(0, NULL);
 442     if (cuda_irq)
 443         enable_irq(cuda_irq);
 444 }
 445 EXPORT_SYMBOL(cuda_poll);
 446
 447 static irqreturn_t
 448 cuda_interrupt(int irq, void *arg)
 449 {
 450     int status;
 451     struct adb_request *req = NULL;
 452     unsigned char ibuf[16];
 453     int ibuf_len = 0;
 454     int complete = 0;
 455
 456     spin_lock(&cuda_lock);
 457
 458     /* On powermacs, this handler is registered for the VIA IRQ. But they use
 459      * just the shift register IRQ -- other VIA interrupt sources are disabled.
 460      * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
 461      * we are polling, the shift register IRQ flag has already been cleared.
 462      */
 463
 464 #ifdef CONFIG_MAC
 465     if (!arg)
 466 #endif
 467     {
 468         if ((in_8(&via[IFR]) & SR_INT) == 0) {
 469             spin_unlock(&cuda_lock);
 470             return IRQ_NONE;
 471         } else {
 472             out_8(&via[IFR], SR_INT);
 473         }
 474     }
 475
 476     status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
 477     /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
 478     switch (cuda_state) {
 479     case idle:
 480         /* CUDA has sent us the first byte of data - unsolicited */
 481         if (status != TREQ)
 482             printk("cuda: state=idle, status=%x\n", status);
 483         (void)in_8(&via[SR]);
 484         out_8(&via[B], in_8(&via[B]) & ~TIP);
 485         cuda_state = reading;
 486         reply_ptr = cuda_rbuf;
 487         reading_reply = 0;
 488         break;
 489
 490     case awaiting_reply:
 491         /* CUDA has sent us the first byte of data of a reply */
 492         if (status != TREQ)
 493             printk("cuda: state=awaiting_reply, status=%x\n", status);
 494         (void)in_8(&via[SR]);
 495         out_8(&via[B], in_8(&via[B]) & ~TIP);
 496         cuda_state = reading;
 497         reply_ptr = current_req->reply;
 498         reading_reply = 1;
 499         break;
 500
 501     case sent_first_byte:
 502         if (status == TREQ + TIP + SR_OUT) {
 503             /* collision */
 504             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 505             (void)in_8(&via[SR]);
 506             out_8(&via[B], in_8(&via[B]) | TIP | TACK);
 507             cuda_state = idle;
 508         } else {
 509             /* assert status == TIP + SR_OUT */
 510             if (status != TIP + SR_OUT)
 511                 printk("cuda: state=sent_first_byte status=%x\n", status);
 512             out_8(&via[SR], current_req->data[1]);
 513             out_8(&via[B], in_8(&via[B]) ^ TACK);
 514             data_index = 2;
 515             cuda_state = sending;
 516         }
 517         break;
 518
 519     case sending:
 520         req = current_req;
 521         if (data_index >= req->nbytes) {
 522             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 523             (void)in_8(&via[SR]);
 524             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 525             req->sent = 1;
 526             if (req->reply_expected) {
 527                 cuda_state = awaiting_reply;
 528             } else {
 529                 current_req = req->next;
 530                 complete = 1;
 531                 /* not sure about this */
 532                 cuda_state = idle;
 533                 cuda_start();
 534             }
 535         } else {
 536             out_8(&via[SR], req->data[data_index++]);
 537             out_8(&via[B], in_8(&via[B]) ^ TACK);
 538         }
 539         break;
 540
 541     case reading:
 542         *reply_ptr++ = in_8(&via[SR]);
 543         if (status == TIP) {
 544             /* that's all folks */
 545             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 546             cuda_state = read_done;
 547         } else {
 548             /* assert status == TIP | TREQ */
 549             if (status != TIP + TREQ)
 550                 printk("cuda: state=reading status=%x\n", status);
 551             out_8(&via[B], in_8(&via[B]) ^ TACK);
 552         }
 553         break;
 554
 555     case read_done:
 556         (void)in_8(&via[SR]);
 557         if (reading_reply) {
 558             req = current_req;
 559             req->reply_len = reply_ptr - req->reply;
 560             if (req->data[0] == ADB_PACKET) {
 561                 /* Have to adjust the reply from ADB commands */
 562                 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
 563                     /* the 0x2 bit indicates no response */
 564                     req->reply_len = 0;
 565                 } else {
 566                     /* leave just the command and result bytes in the reply */
 567                     req->reply_len -= 2;
 568                     memmove(req->reply, req->reply + 2, req->reply_len);
 569                 }
 570             }
 571             current_req = req->next;
 572             complete = 1;
 573         } else {
 574             /* This is tricky. We must break the spinlock to call
 575              * cuda_input. However, doing so means we might get
 576              * re-entered from another CPU getting an interrupt
 577              * or calling cuda_poll(). I ended up using the stack
 578              * (it's only for 16 bytes) and moving the actual
 579              * call to cuda_input to outside of the lock.
 580              */
 581             ibuf_len = reply_ptr - cuda_rbuf;
 582             memcpy(ibuf, cuda_rbuf, ibuf_len);
 583         }
 584         if (status == TREQ) {
 585             out_8(&via[B], in_8(&via[B]) & ~TIP);
 586             cuda_state = reading;
 587             reply_ptr = cuda_rbuf;
 588             reading_reply = 0;
 589         } else {
 590             cuda_state = idle;
 591             cuda_start();
 592         }
 593         break;
 594
 595     default:
 596         printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
 597     }
 598     spin_unlock(&cuda_lock);
 599     if (complete && req) {
 600         void (*done)(struct adb_request *) = req->done;
 601         mb();
 602         req->complete = 1;
 603         /* Here, we assume that if the request has a done member, the
 604          * struct request will survive to setting req->complete to 1
 605          */
 606         if (done)
 607                 (*done)(req);
 608     }
 609     if (ibuf_len)
 610         cuda_input(ibuf, ibuf_len);
 611     return IRQ_HANDLED;
 612 }
 613
 614 static void
 615 cuda_input(unsigned char *buf, int nb)
 616 {
 617     int i;
 618
 619     switch (buf[0]) {
 620     case ADB_PACKET:
 621 #ifdef CONFIG_XMON
 622         if (nb == 5 && buf[2] == 0x2c) {
 623             extern int xmon_wants_key, xmon_adb_keycode;
 624             if (xmon_wants_key) {
 625                 xmon_adb_keycode = buf[3];
 626                 return;
 627             }
 628         }
 629 #endif /* CONFIG_XMON */
 630 #ifdef CONFIG_ADB
 631         adb_input(buf+2, nb-2, buf[1] & 0x40);
 632 #endif /* CONFIG_ADB */
 633         break;
 634
 635     default:
 636         printk("data from cuda (%d bytes):", nb);
 637         for (i = 0; i < nb; ++i)
 638             printk(" %.2x", buf[i]);
 639         printk("\n");
 640     }
 641 }