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 } 634