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