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