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