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/machw.h>
  27 #include <asm/mac_via.h>
  28 #endif
  29 #include <asm/io.h>
  30 #include <asm/system.h>
  31 #include <linux/init.h>
  32
  33 static volatile unsigned char __iomem *via;
  34 static DEFINE_SPINLOCK(cuda_lock);
  35
  36 /* VIA registers - spaced 0x200 bytes apart */
  37 #define RS              0x200           /* skip between registers */
  38 #define B               0               /* B-side data */
  39 #define A               RS              /* A-side data */
  40 #define DIRB            (2*RS)          /* B-side direction (1=output) */
  41 #define DIRA            (3*RS)          /* A-side direction (1=output) */
  42 #define T1CL            (4*RS)          /* Timer 1 ctr/latch (low 8 bits) */
  43 #define T1CH            (5*RS)          /* Timer 1 counter (high 8 bits) */
  44 #define T1LL            (6*RS)          /* Timer 1 latch (low 8 bits) */
  45 #define T1LH            (7*RS)          /* Timer 1 latch (high 8 bits) */
  46 #define T2CL            (8*RS)          /* Timer 2 ctr/latch (low 8 bits) */
  47 #define T2CH            (9*RS)          /* Timer 2 counter (high 8 bits) */
  48 #define SR              (10*RS)         /* Shift register */
  49 #define ACR             (11*RS)         /* Auxiliary control register */
  50 #define PCR             (12*RS)         /* Peripheral control register */
  51 #define IFR             (13*RS)         /* Interrupt flag register */
  52 #define IER             (14*RS)         /* Interrupt enable register */
  53 #define ANH             (15*RS)         /* A-side data, no handshake */
  54
  55 /* Bits in B data register: all active low */
  56 #define TREQ            0x08            /* Transfer request (input) */
  57 #define TACK            0x10            /* Transfer acknowledge (output) */
  58 #define TIP             0x20            /* Transfer in progress (output) */
  59
  60 /* Bits in ACR */
  61 #define SR_CTRL         0x1c            /* Shift register control bits */
  62 #define SR_EXT          0x0c            /* Shift on external clock */
  63 #define SR_OUT          0x10            /* Shift out if 1 */
  64
  65 /* Bits in IFR and IER */
  66 #define IER_SET         0x80            /* set bits in IER */
  67 #define IER_CLR         0               /* clear bits in IER */
  68 #define SR_INT          0x04            /* Shift register full/empty */
  69
  70 static enum cuda_state {
  71     idle,
  72     sent_first_byte,
  73     sending,
  74     reading,
  75     read_done,
  76     awaiting_reply
  77 } cuda_state;
  78
  79 static struct adb_request *current_req;
  80 static struct adb_request *last_req;
  81 static unsigned char cuda_rbuf[16];
  82 static unsigned char *reply_ptr;
  83 static int reading_reply;
  84 static int data_index;
  85 static int cuda_irq;
  86 #ifdef CONFIG_PPC
  87 static struct device_node *vias;
  88 #endif
  89 static int cuda_fully_inited;
  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);
 102 static void cuda_input(unsigned char *buf, int nb);
 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     const 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 = of_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     out_8(&via[IFR], 0x7f);     /* clear interrupts by writing 1s */
 165     out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
 166
 167     /* enable autopoll */
 168     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
 169     while (!req.complete)
 170         cuda_poll();
 171
 172     return 1;
 173
 174  fail:
 175     of_node_put(vias);
 176     vias = NULL;
 177     return 0;
 178 }
 179 #endif /* CONFIG_PPC */
 180
 181 static int __init via_cuda_start(void)
 182 {
 183     if (via == NULL)
 184         return -ENODEV;
 185
 186 #ifdef CONFIG_MAC
 187     cuda_irq = IRQ_MAC_ADB;
 188 #else /* CONFIG_MAC */
 189     cuda_irq = irq_of_parse_and_map(vias, 0);
 190     if (cuda_irq == NO_IRQ) {
 191         printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
 192                vias->full_name);
 193         return -ENODEV;
 194     }
 195 #endif /* CONFIG_MAC */
 196
 197     if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
 198         printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
 199         return -EAGAIN;
 200     }
 201
 202     printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
 203
 204     cuda_fully_inited = 1;
 205     return 0;
 206 }
 207
 208 device_initcall(via_cuda_start);
 209
 210 #ifdef CONFIG_ADB
 211 static int
 212 cuda_probe(void)
 213 {
 214 #ifdef CONFIG_PPC
 215     if (sys_ctrler != SYS_CTRLER_CUDA)
 216         return -ENODEV;
 217 #else
 218     if (macintosh_config->adb_type != MAC_ADB_CUDA)
 219         return -ENODEV;
 220     via = via1;
 221 #endif
 222     return 0;
 223 }
 224
 225 static int __init
 226 cuda_init(void)
 227 {
 228 #ifdef CONFIG_PPC
 229     if (via == NULL)
 230         return -ENODEV;
 231     return 0;
 232 #else
 233     int err = cuda_init_via();
 234     if (err) {
 235         printk(KERN_ERR "cuda_init_via() failed\n");
 236         return -ENODEV;
 237     }
 238     out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
 239
 240     return via_cuda_start();
 241 #endif
 242 }
 243 #endif /* CONFIG_ADB */
 244
 245 #define WAIT_FOR(cond, what)                                    \
 246     do {                                                        \
 247         int x;                                                  \
 248         for (x = 1000; !(cond); --x) {                          \
 249             if (x == 0) {                                       \
 250                 printk("Timeout waiting for " what "\n");       \
 251                 return -ENXIO;                                  \
 252             }                                                   \
 253             udelay(100);                                        \
 254         }                                                       \
 255     } while (0)
 256
 257 static int
 258 cuda_init_via(void)
 259 {
 260     out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
 261     out_8(&via[B], in_8(&via[B]) | TACK | TIP);                 /* negate them */
 262     out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT);    /* SR data in */
 263     (void)in_8(&via[SR]);                                               /* clear any left-over data */
 264 #ifdef CONFIG_PPC
 265     out_8(&via[IER], 0x7f);                                     /* disable interrupts from VIA */
 266     (void)in_8(&via[IER]);
 267 #else
 268     out_8(&via[IER], SR_INT);                                   /* disable SR interrupt from VIA */
 269 #endif
 270
 271     /* delay 4ms and then clear any pending interrupt */
 272     mdelay(4);
 273     (void)in_8(&via[SR]);
 274     out_8(&via[IFR], SR_INT);
 275
 276     /* sync with the CUDA - assert TACK without TIP */
 277     out_8(&via[B], in_8(&via[B]) & ~TACK);
 278
 279     /* wait for the CUDA to assert TREQ in response */
 280     WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
 281
 282     /* wait for the interrupt and then clear it */
 283     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
 284     (void)in_8(&via[SR]);
 285     out_8(&via[IFR], SR_INT);
 286
 287     /* finish the sync by negating TACK */
 288     out_8(&via[B], in_8(&via[B]) | TACK);
 289
 290     /* wait for the CUDA to negate TREQ and the corresponding interrupt */
 291     WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
 292     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
 293     (void)in_8(&via[SR]);
 294     out_8(&via[IFR], SR_INT);
 295     out_8(&via[B], in_8(&via[B]) | TIP);        /* should be unnecessary */
 296
 297     return 0;
 298 }
 299
 300 #ifdef CONFIG_ADB
 301 /* Send an ADB command */
 302 static int
 303 cuda_send_request(struct adb_request *req, int sync)
 304 {
 305     int i;
 306
 307     if ((via == NULL) || !cuda_fully_inited) {
 308         req->complete = 1;
 309         return -ENXIO;
 310     }
 311
 312     req->reply_expected = 1;
 313
 314     i = cuda_write(req);
 315     if (i)
 316         return i;
 317
 318     if (sync) {
 319         while (!req->complete)
 320             cuda_poll();
 321     }
 322     return 0;
 323 }
 324
 325
 326 /* Enable/disable autopolling */
 327 static int
 328 cuda_adb_autopoll(int devs)
 329 {
 330     struct adb_request req;
 331
 332     if ((via == NULL) || !cuda_fully_inited)
 333         return -ENXIO;
 334
 335     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
 336     while (!req.complete)
 337         cuda_poll();
 338     return 0;
 339 }
 340
 341 /* Reset adb bus - how do we do this?? */
 342 static int
 343 cuda_reset_adb_bus(void)
 344 {
 345     struct adb_request req;
 346
 347     if ((via == NULL) || !cuda_fully_inited)
 348         return -ENXIO;
 349
 350     cuda_request(&req, NULL, 2, ADB_PACKET, 0);         /* maybe? */
 351     while (!req.complete)
 352         cuda_poll();
 353     return 0;
 354 }
 355 #endif /* CONFIG_ADB */
 356 /* Construct and send a cuda request */
 357 int
 358 cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
 359              int nbytes, ...)
 360 {
 361     va_list list;
 362     int i;
 363
 364     if (via == NULL) {
 365         req->complete = 1;
 366         return -ENXIO;
 367     }
 368
 369     req->nbytes = nbytes;
 370     req->done = done;
 371     va_start(list, nbytes);
 372     for (i = 0; i < nbytes; ++i)
 373         req->data[i] = va_arg(list, int);
 374     va_end(list);
 375     req->reply_expected = 1;
 376     return cuda_write(req);
 377 }
 378
 379 static int
 380 cuda_write(struct adb_request *req)
 381 {
 382     unsigned long flags;
 383
 384     if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
 385         req->complete = 1;
 386         return -EINVAL;
 387     }
 388     req->next = NULL;
 389     req->sent = 0;
 390     req->complete = 0;
 391     req->reply_len = 0;
 392
 393     spin_lock_irqsave(&cuda_lock, flags);
 394     if (current_req != 0) {
 395         last_req->next = req;
 396         last_req = req;
 397     } else {
 398         current_req = req;
 399         last_req = req;
 400         if (cuda_state == idle)
 401             cuda_start();
 402     }
 403     spin_unlock_irqrestore(&cuda_lock, flags);
 404
 405     return 0;
 406 }
 407
 408 static void
 409 cuda_start(void)
 410 {
 411     struct adb_request *req;
 412
 413     /* assert cuda_state == idle */
 414     /* get the packet to send */
 415     req = current_req;
 416     if (req == 0)
 417         return;
 418     if ((in_8(&via[B]) & TREQ) == 0)
 419         return;                 /* a byte is coming in from the CUDA */
 420
 421     /* set the shift register to shift out and send a byte */
 422     out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
 423     out_8(&via[SR], req->data[0]);
 424     out_8(&via[B], in_8(&via[B]) & ~TIP);
 425     cuda_state = sent_first_byte;
 426 }
 427
 428 void
 429 cuda_poll(void)
 430 {
 431     /* cuda_interrupt only takes a normal lock, we disable
 432      * interrupts here to avoid re-entering and thus deadlocking.
 433      */
 434     disable_irq(cuda_irq);
 435     cuda_interrupt(0, NULL);
 436     enable_irq(cuda_irq);
 437 }
 438
 439 static irqreturn_t
 440 cuda_interrupt(int irq, void *arg)
 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
 448     spin_lock(&cuda_lock);
 449
 450     /* On powermacs, this handler is registered for the VIA IRQ. But it uses
 451      * just the shift register IRQ -- other VIA interrupt sources are disabled.
 452      * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
 453      * we are polling, the shift register IRQ flag has already been cleared.
 454      */
 455
 456 #ifdef CONFIG_MAC
 457     if (!arg)
 458 #endif
 459     {
 460         if ((in_8(&via[IFR]) & SR_INT) == 0) {
 461             spin_unlock(&cuda_lock);
 462             return IRQ_NONE;
 463         } else {
 464             out_8(&via[IFR], SR_INT);
 465         }
 466     }
 467
 468     status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
 469     /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
 470     switch (cuda_state) {
 471     case idle:
 472         /* CUDA has sent us the first byte of data - unsolicited */
 473         if (status != TREQ)
 474             printk("cuda: state=idle, status=%x\n", status);
 475         (void)in_8(&via[SR]);
 476         out_8(&via[B], in_8(&via[B]) & ~TIP);
 477         cuda_state = reading;
 478         reply_ptr = cuda_rbuf;
 479         reading_reply = 0;
 480         break;
 481
 482     case awaiting_reply:
 483         /* CUDA has sent us the first byte of data of a reply */
 484         if (status != TREQ)
 485             printk("cuda: state=awaiting_reply, status=%x\n", status);
 486         (void)in_8(&via[SR]);
 487         out_8(&via[B], in_8(&via[B]) & ~TIP);
 488         cuda_state = reading;
 489         reply_ptr = current_req->reply;
 490         reading_reply = 1;
 491         break;
 492
 493     case sent_first_byte:
 494         if (status == TREQ + TIP + SR_OUT) {
 495             /* collision */
 496             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 497             (void)in_8(&via[SR]);
 498             out_8(&via[B], in_8(&via[B]) | TIP | TACK);
 499             cuda_state = idle;
 500         } else {
 501             /* assert status == TIP + SR_OUT */
 502             if (status != TIP + SR_OUT)
 503                 printk("cuda: state=sent_first_byte status=%x\n", status);
 504             out_8(&via[SR], current_req->data[1]);
 505             out_8(&via[B], in_8(&via[B]) ^ TACK);
 506             data_index = 2;
 507             cuda_state = sending;
 508         }
 509         break;
 510
 511     case sending:
 512         req = current_req;
 513         if (data_index >= req->nbytes) {
 514             out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
 515             (void)in_8(&via[SR]);
 516             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 517             req->sent = 1;
 518             if (req->reply_expected) {
 519                 cuda_state = awaiting_reply;
 520             } else {
 521                 current_req = req->next;
 522                 complete = 1;
 523                 /* not sure about this */
 524                 cuda_state = idle;
 525                 cuda_start();
 526             }
 527         } else {
 528             out_8(&via[SR], req->data[data_index++]);
 529             out_8(&via[B], in_8(&via[B]) ^ TACK);
 530         }
 531         break;
 532
 533     case reading:
 534         *reply_ptr++ = in_8(&via[SR]);
 535         if (status == TIP) {
 536             /* that's all folks */
 537             out_8(&via[B], in_8(&via[B]) | TACK | TIP);
 538             cuda_state = read_done;
 539         } else {
 540             /* assert status == TIP | TREQ */
 541             if (status != TIP + TREQ)
 542                 printk("cuda: state=reading status=%x\n", status);
 543             out_8(&via[B], in_8(&via[B]) ^ TACK);
 544         }
 545         break;
 546
 547     case read_done:
 548         (void)in_8(&via[SR]);
 549         if (reading_reply) {
 550             req = current_req;
 551             req->reply_len = reply_ptr - req->reply;
 552             if (req->data[0] == ADB_PACKET) {
 553                 /* Have to adjust the reply from ADB commands */
 554                 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
 555                     /* the 0x2 bit indicates no response */
 556                     req->reply_len = 0;
 557                 } else {
 558                     /* leave just the command and result bytes in the reply */
 559                     req->reply_len -= 2;
 560                     memmove(req->reply, req->reply + 2, req->reply_len);
 561                 }
 562             }
 563             current_req = req->next;
 564             complete = 1;
 565         } else {
 566             /* This is tricky. We must break the spinlock to call
 567              * cuda_input. However, doing so means we might get
 568              * re-entered from another CPU getting an interrupt
 569              * or calling cuda_poll(). I ended up using the stack
 570              * (it's only for 16 bytes) and moving the actual
 571              * call to cuda_input to outside of the lock.
 572              */
 573             ibuf_len = reply_ptr - cuda_rbuf;
 574             memcpy(ibuf, cuda_rbuf, ibuf_len);
 575         }
 576         if (status == TREQ) {
 577             out_8(&via[B], in_8(&via[B]) & ~TIP);
 578             cuda_state = reading;
 579             reply_ptr = cuda_rbuf;
 580             reading_reply = 0;
 581         } else {
 582             cuda_state = idle;
 583             cuda_start();
 584         }
 585         break;
 586
 587     default:
 588         printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
 589     }
 590     spin_unlock(&cuda_lock);
 591     if (complete && req) {
 592         void (*done)(struct adb_request *) = req->done;
 593         mb();
 594         req->complete = 1;
 595         /* Here, we assume that if the request has a done member, the
 596          * struct request will survive to setting req->complete to 1
 597          */
 598         if (done)
 599                 (*done)(req);
 600     }
 601     if (ibuf_len)
 602         cuda_input(ibuf, ibuf_len);
 603     return IRQ_HANDLED;
 604 }
 605
 606 static void
 607 cuda_input(unsigned char *buf, int nb)
 608 {
 609     int i;
 610
 611     switch (buf[0]) {
 612     case ADB_PACKET:
 613 #ifdef CONFIG_XMON
 614         if (nb == 5 && buf[2] == 0x2c) {
 615             extern int xmon_wants_key, xmon_adb_keycode;
 616             if (xmon_wants_key) {
 617                 xmon_adb_keycode = buf[3];
 618                 return;
 619             }
 620         }
 621 #endif /* CONFIG_XMON */
 622 #ifdef CONFIG_ADB
 623         adb_input(buf+2, nb-2, buf[1] & 0x40);
 624 #endif /* CONFIG_ADB */
 625         break;
 626
 627     default:
 628         printk("data from cuda (%d bytes):", nb);
 629         for (i = 0; i < nb; ++i)
 630             printk(" %.2x", buf[i]);
 631         printk("\n");
 632     }
 633 }