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 <asm/system.h>
  30 #include <linux/init.h>
  31
  32 static volatile unsigned char __iomem *via;
  33 static DEFINE_SPINLOCK(cuda_lock);
  34
  35 /* VIA registers - spaced 0x200 bytes apart */
  36 #define RS              0x200           /* skip between registers */
  37 #define B               0               /* B-side data */
  38 #define A               RS              /* A-side data */
  39 #define DIRB            (2*RS)          /* B-side direction (1=output) */
  40 #define DIRA            (3*RS)          /* A-side direction (1=output) */
  41 #define T1CL            (4*RS)          /* Timer 1 ctr/latch (low 8 bits) */
  42 #define T1CH            (5*RS)          /* Timer 1 counter (high 8 bits) */
  43 #define T1LL            (6*RS)          /* Timer 1 latch (low 8 bits) */
  44 #define T1LH            (7*RS)          /* Timer 1 latch (high 8 bits) */
  45 #define T2CL            (8*RS)          /* Timer 2 ctr/latch (low 8 bits) */
  46 #define T2CH            (9*RS)          /* Timer 2 counter (high 8 bits) */
  47 #define SR              (10*RS)         /* Shift register */
  48 #define ACR             (11*RS)         /* Auxiliary control register */
  49 #define PCR             (12*RS)         /* Peripheral control register */
  50 #define IFR             (13*RS)         /* Interrupt flag register */
  51 #define IER             (14*RS)         /* Interrupt enable register */
  52 #define ANH             (15*RS)         /* A-side data, no handshake */
  53
  54 /* Bits in B data register: all active low */
  55 #define TREQ            0x08            /* Transfer request (input) */
  56 #define TACK            0x10            /* Transfer acknowledge (output) */
  57 #define TIP             0x20            /* Transfer in progress (output) */
  58
  59 /* Bits in ACR */
  60 #define SR_CTRL         0x1c            /* Shift register control bits */
  61 #define SR_EXT          0x0c            /* Shift on external clock */
  62 #define SR_OUT          0x10            /* Shift out if 1 */
  63
  64 /* Bits in IFR and IER */
  65 #define IER_SET         0x80            /* set bits in IER */
  66 #define IER_CLR         0               /* clear bits in IER */
  67 #define SR_INT          0x04            /* Shift register full/empty */
  68
  69 static enum cuda_state {
  70     idle,
  71     sent_first_byte,
  72     sending,
  73     reading,
  74     read_done,
  75     awaiting_reply
  76 } cuda_state;
  77
  78 static struct adb_request *current_req;
  79 static struct adb_request *last_req;
  80 static unsigned char cuda_rbuf[16];
  81 static unsigned char *reply_ptr;
  82 static int reading_reply;
  83 static int data_index;
  84 static int cuda_irq;
  85 #ifdef CONFIG_PPC
  86 static struct device_node *vias;
  87 #endif
  88 static int cuda_fully_inited;
  89
  90 #ifdef CONFIG_ADB
  91 static int cuda_probe(void);
  92 static int cuda_send_request(struct adb_request *req, int sync);
  93 static int cuda_adb_autopoll(int devs);
  94 static int cuda_reset_adb_bus(void);
  95 #endif /* CONFIG_ADB */
  96
  97 static int cuda_init_via(void);
  98 static void cuda_start(void);
  99 static irqreturn_t cuda_interrupt(int irq, void *arg);
 100 static void cuda_input(unsigned char *buf, int nb);
 101 void cuda_poll(void);
 102 static int cuda_write(struct adb_request *req);
 103
 104 int cuda_request(struct adb_request *req,
 105                  void (*done)(struct adb_request *), int nbytes, ...);
 106
 107 #ifdef CONFIG_ADB
 108 struct adb_driver via_cuda_driver = {
 109         .name         = "CUDA",
 110         .probe        = cuda_probe,
 111         .send_request = cuda_send_request,
 112         .autopoll     = cuda_adb_autopoll,
 113         .poll         = cuda_poll,
 114         .reset_bus    = cuda_reset_adb_bus,
 115 };
 116 #endif /* CONFIG_ADB */
 117
 118 #ifdef CONFIG_MAC
 119 int __init find_via_cuda(void)
 120 {
 121     struct adb_request req;
 122     int err;
 123
 124     if (macintosh_config->adb_type != MAC_ADB_CUDA)
 125         return 0;
 126
 127     via = via1;
 128     cuda_state = idle;
 129
 130     err = cuda_init_via();
 131     if (err) {
 132         printk(KERN_ERR "cuda_init_via() failed\n");
 133         via = NULL;
 134         return 0;
 135     }
 136
 137     /* enable autopoll */
 138     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
 139     while (!req.complete)
 140         cuda_poll();
 141
 142     return 1;
 143 }
 144 #else
 145 int __init find_via_cuda(void)
 146 {
 147     struct adb_request req;
 148     phys_addr_t taddr;
 149     const u32 *reg;
 150     int err;
 151
 152     if (vias != 0)
 153         return 1;
 154     vias = of_find_node_by_name(NULL, "via-cuda");
 155     if (vias == 0)
 156         return 0;
 157
 158     reg = of_get_property(vias, "reg", NULL);
 159     if (reg == NULL) {
 160             printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
 161             goto fail;
 162     }
 163     taddr = of_translate_address(vias, reg);
 164     if (taddr == 0) {
 165             printk(KERN_ERR "via-cuda: Can't translate address !\n");
 166             goto fail;
 167     }
 168     via = ioremap(taddr, 0x2000);
 169     if (via == NULL) {
 170             printk(KERN_ERR "via-cuda: Can't map address !\n");
 171             goto fail;
 172     }
 173
 174     cuda_state = idle;
 175     sys_ctrler = SYS_CTRLER_CUDA;
 176
 177     err = cuda_init_via();
 178     if (err) {
 179         printk(KERN_ERR "cuda_init_via() failed\n");
 180         via = NULL;
 181         return 0;
 182     }
 183
 184     /* Clear and enable interrupts, but only on PPC. On 68K it's done  */
 185     /* for us by the main VIA driver in arch/m68k/mac/via.c        */
 186
 187     out_8(&via[IFR], 0x7f);     /* clear interrupts by writing 1s */
 188     out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
 189
 190     /* enable autopoll */
 191     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
 192     while (!req.complete)
 193         cuda_poll();
 194
 195     return 1;
 196
 197  fail:
 198     of_node_put(vias);
 199     vias = NULL;
 200     return 0;
 201 }
 202 #endif /* !defined CONFIG_MAC */
 203
 204 static int __init via_cuda_start(void)
 205 {
 206     if (via == NULL)
 207         return -ENODEV;
 208
 209 #ifdef CONFIG_MAC
 210     cuda_irq = IRQ_MAC_ADB;
 211 #else
 212     cuda_irq = irq_of_parse_and_map(vias, 0);
 213     if (cuda_irq == NO_IRQ) {
 214         printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
 215                vias->full_name);
 216         return -ENODEV;
 217     }
 218 #endif
 219
 220     if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
 221         printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
 222         return -EAGAIN;
 223     }
 224
 225     printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
 226
 227     cuda_fully_inited = 1;
 228     return 0;
 229 }
 230
 231 device_initcall(via_cuda_start);
 232
 233 #ifdef CONFIG_ADB
 234 static int
 235 cuda_probe(void)
 236 {
 237 #ifdef CONFIG_PPC
 238     if (sys_ctrler != SYS_CTRLER_CUDA)
 239         return -ENODEV;
 240 #else
 241     if (macintosh_config->adb_type != MAC_ADB_CUDA)
 242         return -ENODEV;
 243 #endif
 244     if (via == NULL)
 245         return -ENODEV;
 246     return 0;
 247 }
 248 #endif /* CONFIG_ADB */
 249
 250 #define WAIT_FOR(cond, what)                                    \
 251     do {                                                        \
 252         int x;                                                  \
 253         for (x = 1000; !(cond); --x) {                          \
 254             if (x == 0) {                                       \
 255                 printk("Timeout waiting for " what "\n");       \
 256                 return -ENXIO;                                  \
 257             }                                                   \
 258             udelay(100);                                        \
 259         }                                                       \
 260     } while (0)
 261
 262 static int
 263 cuda_init_via(void)
 264 {
 265     out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
 266     out_8(&via[B], in_8(&via[B]) | TACK | TIP);                 /* negate them */
 267     out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT);    /* SR data in */
 268     (void)in_8(&via[SR]);                                               /* clear any left-over data */
 269 #ifdef CONFIG_PPC
 270     out_8(&via[IER], 0x7f);                                     /* disable interrupts from VIA */
 271     (void)in_8(&via[IER]);
 272 #else
 273     out_8(&via[IER], SR_INT);                                   /* disable SR interrupt from VIA */
 274 #endif
 275
 276     /* delay 4ms and then clear any pending interrupt */
 277     mdelay(4);
 278     (void)in_8(&via[SR]);
 279     out_8(&via[IFR], SR_INT);
 280
 281     /* sync with the CUDA - assert TACK without TIP */
 282     out_8(&via[B], in_8(&via[B]) & ~TACK);
 283
 284     /* wait for the CUDA to assert TREQ in response */
 285     WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
 286
 287     /* wait for the interrupt and then clear it */
 288     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
 289     (void)in_8(&via[SR]);
 290     out_8(&via[IFR], SR_INT);
 291
 292     /* finish the sync by negating TACK */
 293     out_8(&via[B], in_8(&via[B]) | TACK);
 294
 295     /* wait for the CUDA to negate TREQ and the corresponding interrupt */
 296     WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
 297     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
 298     (void)in_8(&via[SR]);
 299     out_8(&via[IFR], SR_INT);
 300     out_8(&via[B], in_8(&via[B]) | TIP);        /* should be unnecessary */
 301
 302     return 0;
 303 }
 304
 305 #ifdef CONFIG_ADB
 306 /* Send an ADB command */
 307 static int
 308 cuda_send_request(struct adb_request *req, int sync)
 309 {
 310     int i;
 311
 312     if ((via == NULL) || !cuda_fully_inited) {
 313         req->complete = 1;
 314         return -ENXIO;
 315     }
 316
 317     req->reply_expected = 1;
 318
 319     i = cuda_write(req);
 320     if (i)
 321         return i;
 322
 323     if (sync) {
 324         while (!req->complete)
 325             cuda_poll();
 326     }
 327     return 0;
 328 }
 329
 330
 331 /* Enable/disable autopolling */
 332 static int
 333 cuda_adb_autopoll(int devs)
 334 {
 335     struct adb_request req;
 336
 337     if ((via == NULL) || !cuda_fully_inited)
 338         return -ENXIO;
 339
 340     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
 341     while (!req.complete)
 342         cuda_poll();
 343     return 0;
 344 }
 345
 346 /* Reset adb bus - how do we do this?? */
 347 static int
 348 cuda_reset_adb_bus(void)
 349 {
 350     struct adb_request req;
 351
 352     if ((via == NULL) || !cuda_fully_inited)
 353         return -ENXIO;
 354
 355     cuda_request(&req, NULL, 2, ADB_PACKET, 0);         /* maybe? */
 356     while (!req.complete)
 357         cuda_poll();
 358     return 0;
 359 }
 360 #endif /* CONFIG_ADB */
 361 /* Construct and send a cuda request */
 362 int
 363 cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
 364              int nbytes, ...)
 365 {
 366     va_list list;
 367     int i;
 368
 369     if (via == NULL) {
 370         req->complete = 1;
 371         return -ENXIO;
 372     }
 373
 374     req->nbytes = nbytes;
 375     req->done = done;
 376     va_start(list, nbytes);
 377     for (i = 0; i < nbytes; ++i)
 378         req->data[i] = va_arg(list, int);
 379     va_end(list);
 380     req->reply_expected = 1;
 381     return cuda_write(req);
 382 }
 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
 446 static irqreturn_t
 447 cuda_interrupt(int irq, void *arg)
 448 {
 449     int status;
 450     struct adb_request *req = NULL;
 451     unsigned char ibuf[16];
 452     int ibuf_len = 0;
 453     int complete = 0;
 454
 455     spin_lock(&cuda_lock);
 456
 457     /* On powermacs, this handler is registered for the VIA IRQ. But they use
 458      * just the shift register IRQ -- other VIA interrupt sources are disabled.
 459      * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
 460      * we are polling, the shift register IRQ flag has already been cleared.
 461      */
 462
 463 #ifdef CONFIG_MAC
 464     if (!arg)
 465 #endif
 466     {
 467         if ((in_8(&via[IFR]) & SR_INT) == 0) {
 468             spin_unlock(&cuda_lock);
 469             return IRQ_NONE;
 470         } else {
 471             out_8(&via[IFR], SR_INT);
 472         }
 473     }
 474
 475     status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
 476     /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
 477     switch (cuda_state) {
 478     case idle:
 479         /* CUDA has sent us the first byte of data - unsolicited */
 480         if (status != TREQ)
 481             printk("cuda: state=idle, status=%x\n", status);
 482         (void)in_8(&via[SR]);
 483         out_8(&via[B], in_8(&via[B]) & ~TIP);
 484         cuda_state = reading;
 485         reply_ptr = cuda_rbuf;
 486         reading_reply = 0;
 487         break;
 488
 489     case awaiting_reply:
 490         /* CUDA has sent us the first byte of data of a reply */
 491         if (status != TREQ)
 492             printk("cuda: state=awaiting_reply, status=%x\n", status);
 493         (void)in_8(&via[SR]);
 494         out_8(&via[B], in_8(&via[B]) & ~TIP);
 495         cuda_state = reading;
 496         reply_ptr = current_req->reply;
 497         reading_reply = 1;
 498         break;
 499
 500     case sent_first_byte:
 501         if (status == TREQ + TIP + SR_OUT) {
 502             /* collision */
 503             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 504             (void)in_8(&via[SR]);
 505             out_8(&via[B], in_8(&via[B]) | TIP | TACK);
 506             cuda_state = idle;
 507         } else {
 508             /* assert status == TIP + SR_OUT */
 509             if (status != TIP + SR_OUT)
 510                 printk("cuda: state=sent_first_byte status=%x\n", status);
 511             out_8(&via[SR], current_req->data[1]);
 512             out_8(&via[B], in_8(&via[B]) ^ TACK);
 513             data_index = 2;
 514             cuda_state = sending;
 515         }
 516         break;
 517
 518     case sending:
 519         req = current_req;
 520         if (data_index >= req->nbytes) {
 521             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 522             (void)in_8(&via[SR]);
 523             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 524             req->sent = 1;
 525             if (req->reply_expected) {
 526                 cuda_state = awaiting_reply;
 527             } else {
 528                 current_req = req->next;
 529                 complete = 1;
 530                 /* not sure about this */
 531                 cuda_state = idle;
 532                 cuda_start();
 533             }
 534         } else {
 535             out_8(&via[SR], req->data[data_index++]);
 536             out_8(&via[B], in_8(&via[B]) ^ TACK);
 537         }
 538         break;
 539
 540     case reading:
 541         *reply_ptr++ = in_8(&via[SR]);
 542         if (status == TIP) {
 543             /* that's all folks */
 544             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 545             cuda_state = read_done;
 546         } else {
 547             /* assert status == TIP | TREQ */
 548             if (status != TIP + TREQ)
 549                 printk("cuda: state=reading status=%x\n", status);
 550             out_8(&via[B], in_8(&via[B]) ^ TACK);
 551         }
 552         break;
 553
 554     case read_done:
 555         (void)in_8(&via[SR]);
 556         if (reading_reply) {
 557             req = current_req;
 558             req->reply_len = reply_ptr - req->reply;
 559             if (req->data[0] == ADB_PACKET) {
 560                 /* Have to adjust the reply from ADB commands */
 561                 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
 562                     /* the 0x2 bit indicates no response */
 563                     req->reply_len = 0;
 564                 } else {
 565                     /* leave just the command and result bytes in the reply */
 566                     req->reply_len -= 2;
 567                     memmove(req->reply, req->reply + 2, req->reply_len);
 568                 }
 569             }
 570             current_req = req->next;
 571             complete = 1;
 572         } else {
 573             /* This is tricky. We must break the spinlock to call
 574              * cuda_input. However, doing so means we might get
 575              * re-entered from another CPU getting an interrupt
 576              * or calling cuda_poll(). I ended up using the stack
 577              * (it's only for 16 bytes) and moving the actual
 578              * call to cuda_input to outside of the lock.
 579              */
 580             ibuf_len = reply_ptr - cuda_rbuf;
 581             memcpy(ibuf, cuda_rbuf, ibuf_len);
 582         }
 583         if (status == TREQ) {
 584             out_8(&via[B], in_8(&via[B]) & ~TIP);
 585             cuda_state = reading;
 586             reply_ptr = cuda_rbuf;
 587             reading_reply = 0;
 588         } else {
 589             cuda_state = idle;
 590             cuda_start();
 591         }
 592         break;
 593
 594     default:
 595         printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
 596     }
 597     spin_unlock(&cuda_lock);
 598     if (complete && req) {
 599         void (*done)(struct adb_request *) = req->done;
 600         mb();
 601         req->complete = 1;
 602         /* Here, we assume that if the request has a done member, the
 603          * struct request will survive to setting req->complete to 1
 604          */
 605         if (done)
 606                 (*done)(req);
 607     }
 608     if (ibuf_len)
 609         cuda_input(ibuf, ibuf_len);
 610     return IRQ_HANDLED;
 611 }
 612
 613 static void
 614 cuda_input(unsigned char *buf, int nb)
 615 {
 616     int i;
 617
 618     switch (buf[0]) {
 619     case ADB_PACKET:
 620 #ifdef CONFIG_XMON
 621         if (nb == 5 && buf[2] == 0x2c) {
 622             extern int xmon_wants_key, xmon_adb_keycode;
 623             if (xmon_wants_key) {
 624                 xmon_adb_keycode = buf[3];
 625                 return;
 626             }
 627         }
 628 #endif /* CONFIG_XMON */
 629 #ifdef CONFIG_ADB
 630         adb_input(buf+2, nb-2, buf[1] & 0x40);
 631 #endif /* CONFIG_ADB */
 632         break;
 633
 634     default:
 635         printk("data from cuda (%d bytes):", nb);
 636         for (i = 0; i < nb; ++i)
 637             printk(" %.2x", buf[i]);
 638         printk("\n");
 639     }
 640 }