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 <linux/init.h> 30 31 static volatile unsigned char __iomem *via; 32 static DEFINE_SPINLOCK(cuda_lock); 33 34 /* VIA registers - spaced 0x200 bytes apart */ 35 #define RS 0x200 /* skip between registers */ 36 #define B 0 /* B-side data */ 37 #define A RS /* A-side data */ 38 #define DIRB (2*RS) /* B-side direction (1=output) */ 39 #define DIRA (3*RS) /* A-side direction (1=output) */ 40 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 41 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 42 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 43 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 44 #define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */ 45 #define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */ 46 #define SR (10*RS) /* Shift register */ 47 #define ACR (11*RS) /* Auxiliary control register */ 48 #define PCR (12*RS) /* Peripheral control register */ 49 #define IFR (13*RS) /* Interrupt flag register */ 50 #define IER (14*RS) /* Interrupt enable register */ 51 #define ANH (15*RS) /* A-side data, no handshake */ 52 53 /* Bits in B data register: all active low */ 54 #define TREQ 0x08 /* Transfer request (input) */ 55 #define TACK 0x10 /* Transfer acknowledge (output) */ 56 #define TIP 0x20 /* Transfer in progress (output) */ 57 58 /* Bits in ACR */ 59 #define SR_CTRL 0x1c /* Shift register control bits */ 60 #define SR_EXT 0x0c /* Shift on external clock */ 61 #define SR_OUT 0x10 /* Shift out if 1 */ 62 63 /* Bits in IFR and IER */ 64 #define IER_SET 0x80 /* set bits in IER */ 65 #define IER_CLR 0 /* clear bits in IER */ 66 #define SR_INT 0x04 /* Shift register full/empty */ 67 68 static enum cuda_state { 69 idle, 70 sent_first_byte, 71 sending, 72 reading, 73 read_done, 74 awaiting_reply 75 } cuda_state; 76 77 static struct adb_request *current_req; 78 static struct adb_request *last_req; 79 static unsigned char cuda_rbuf[16]; 80 static unsigned char *reply_ptr; 81 static int reading_reply; 82 static int data_index; 83 static int cuda_irq; 84 #ifdef CONFIG_PPC 85 static struct device_node *vias; 86 #endif 87 static int cuda_fully_inited; 88 89 #ifdef CONFIG_ADB 90 static int cuda_probe(void); 91 static int cuda_send_request(struct adb_request *req, int sync); 92 static int cuda_adb_autopoll(int devs); 93 static int cuda_reset_adb_bus(void); 94 #endif /* CONFIG_ADB */ 95 96 static int cuda_init_via(void); 97 static void cuda_start(void); 98 static irqreturn_t cuda_interrupt(int irq, void *arg); 99 static void cuda_input(unsigned char *buf, int nb); 100 void cuda_poll(void); 101 static int cuda_write(struct adb_request *req); 102 103 int cuda_request(struct adb_request *req, 104 void (*done)(struct adb_request *), int nbytes, ...); 105 106 #ifdef CONFIG_ADB 107 struct adb_driver via_cuda_driver = { 108 .name = "CUDA", 109 .probe = cuda_probe, 110 .send_request = cuda_send_request, 111 .autopoll = cuda_adb_autopoll, 112 .poll = cuda_poll, 113 .reset_bus = cuda_reset_adb_bus, 114 }; 115 #endif /* CONFIG_ADB */ 116 117 #ifdef CONFIG_MAC 118 int __init find_via_cuda(void) 119 { 120 struct adb_request req; 121 int err; 122 123 if (macintosh_config->adb_type != MAC_ADB_CUDA) 124 return 0; 125 126 via = via1; 127 cuda_state = idle; 128 129 err = cuda_init_via(); 130 if (err) { 131 printk(KERN_ERR "cuda_init_via() failed\n"); 132 via = NULL; 133 return 0; 134 } 135 136 /* enable autopoll */ 137 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); 138 while (!req.complete) 139 cuda_poll(); 140 141 return 1; 142 } 143 #else 144 int __init find_via_cuda(void) 145 { 146 struct adb_request req; 147 phys_addr_t taddr; 148 const u32 *reg; 149 int err; 150 151 if (vias != 0) 152 return 1; 153 vias = of_find_node_by_name(NULL, "via-cuda"); 154 if (vias == 0) 155 return 0; 156 157 reg = of_get_property(vias, "reg", NULL); 158 if (reg == NULL) { 159 printk(KERN_ERR "via-cuda: No \"reg\" property !\n"); 160 goto fail; 161 } 162 taddr = of_translate_address(vias, reg); 163 if (taddr == 0) { 164 printk(KERN_ERR "via-cuda: Can't translate address !\n"); 165 goto fail; 166 } 167 via = ioremap(taddr, 0x2000); 168 if (via == NULL) { 169 printk(KERN_ERR "via-cuda: Can't map address !\n"); 170 goto fail; 171 } 172 173 cuda_state = idle; 174 sys_ctrler = SYS_CTRLER_CUDA; 175 176 err = cuda_init_via(); 177 if (err) { 178 printk(KERN_ERR "cuda_init_via() failed\n"); 179 via = NULL; 180 return 0; 181 } 182 183 /* Clear and enable interrupts, but only on PPC. On 68K it's done */ 184 /* for us by the main VIA driver in arch/m68k/mac/via.c */ 185 186 out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */ 187 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */ 188 189 /* enable autopoll */ 190 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); 191 while (!req.complete) 192 cuda_poll(); 193 194 return 1; 195 196 fail: 197 of_node_put(vias); 198 vias = NULL; 199 return 0; 200 } 201 #endif /* !defined CONFIG_MAC */ 202 203 static int __init via_cuda_start(void) 204 { 205 if (via == NULL) 206 return -ENODEV; 207 208 #ifdef CONFIG_MAC 209 cuda_irq = IRQ_MAC_ADB; 210 #else 211 cuda_irq = irq_of_parse_and_map(vias, 0); 212 if (cuda_irq == NO_IRQ) { 213 printk(KERN_ERR "via-cuda: can't map interrupts for %s\n", 214 vias->full_name); 215 return -ENODEV; 216 } 217 #endif 218 219 if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) { 220 printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq); 221 return -EAGAIN; 222 } 223 224 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n"); 225 226 cuda_fully_inited = 1; 227 return 0; 228 } 229 230 device_initcall(via_cuda_start); 231 232 #ifdef CONFIG_ADB 233 static int 234 cuda_probe(void) 235 { 236 #ifdef CONFIG_PPC 237 if (sys_ctrler != SYS_CTRLER_CUDA) 238 return -ENODEV; 239 #else 240 if (macintosh_config->adb_type != MAC_ADB_CUDA) 241 return -ENODEV; 242 #endif 243 if (via == NULL) 244 return -ENODEV; 245 return 0; 246 } 247 #endif /* CONFIG_ADB */ 248 249 #define WAIT_FOR(cond, what) \ 250 do { \ 251 int x; \ 252 for (x = 1000; !(cond); --x) { \ 253 if (x == 0) { \ 254 printk("Timeout waiting for " what "\n"); \ 255 return -ENXIO; \ 256 } \ 257 udelay(100); \ 258 } \ 259 } while (0) 260 261 static int 262 cuda_init_via(void) 263 { 264 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */ 265 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */ 266 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */ 267 (void)in_8(&via[SR]); /* clear any left-over data */ 268 #ifdef CONFIG_PPC 269 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */ 270 (void)in_8(&via[IER]); 271 #else 272 out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */ 273 #endif 274 275 /* delay 4ms and then clear any pending interrupt */ 276 mdelay(4); 277 (void)in_8(&via[SR]); 278 out_8(&via[IFR], SR_INT); 279 280 /* sync with the CUDA - assert TACK without TIP */ 281 out_8(&via[B], in_8(&via[B]) & ~TACK); 282 283 /* wait for the CUDA to assert TREQ in response */ 284 WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync"); 285 286 /* wait for the interrupt and then clear it */ 287 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)"); 288 (void)in_8(&via[SR]); 289 out_8(&via[IFR], SR_INT); 290 291 /* finish the sync by negating TACK */ 292 out_8(&via[B], in_8(&via[B]) | TACK); 293 294 /* wait for the CUDA to negate TREQ and the corresponding interrupt */ 295 WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)"); 296 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)"); 297 (void)in_8(&via[SR]); 298 out_8(&via[IFR], SR_INT); 299 out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */ 300 301 return 0; 302 } 303 304 #ifdef CONFIG_ADB 305 /* Send an ADB command */ 306 static int 307 cuda_send_request(struct adb_request *req, int sync) 308 { 309 int i; 310 311 if ((via == NULL) || !cuda_fully_inited) { 312 req->complete = 1; 313 return -ENXIO; 314 } 315 316 req->reply_expected = 1; 317 318 i = cuda_write(req); 319 if (i) 320 return i; 321 322 if (sync) { 323 while (!req->complete) 324 cuda_poll(); 325 } 326 return 0; 327 } 328 329 330 /* Enable/disable autopolling */ 331 static int 332 cuda_adb_autopoll(int devs) 333 { 334 struct adb_request req; 335 336 if ((via == NULL) || !cuda_fully_inited) 337 return -ENXIO; 338 339 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0)); 340 while (!req.complete) 341 cuda_poll(); 342 return 0; 343 } 344 345 /* Reset adb bus - how do we do this?? */ 346 static int 347 cuda_reset_adb_bus(void) 348 { 349 struct adb_request req; 350 351 if ((via == NULL) || !cuda_fully_inited) 352 return -ENXIO; 353 354 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */ 355 while (!req.complete) 356 cuda_poll(); 357 return 0; 358 } 359 #endif /* CONFIG_ADB */ 360 /* Construct and send a cuda request */ 361 int 362 cuda_request(struct adb_request *req, void (*done)(struct adb_request *), 363 int nbytes, ...) 364 { 365 va_list list; 366 int i; 367 368 if (via == NULL) { 369 req->complete = 1; 370 return -ENXIO; 371 } 372 373 req->nbytes = nbytes; 374 req->done = done; 375 va_start(list, nbytes); 376 for (i = 0; i < nbytes; ++i) 377 req->data[i] = va_arg(list, int); 378 va_end(list); 379 req->reply_expected = 1; 380 return cuda_write(req); 381 } 382 383 static int 384 cuda_write(struct adb_request *req) 385 { 386 unsigned long flags; 387 388 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) { 389 req->complete = 1; 390 return -EINVAL; 391 } 392 req->next = NULL; 393 req->sent = 0; 394 req->complete = 0; 395 req->reply_len = 0; 396 397 spin_lock_irqsave(&cuda_lock, flags); 398 if (current_req != 0) { 399 last_req->next = req; 400 last_req = req; 401 } else { 402 current_req = req; 403 last_req = req; 404 if (cuda_state == idle) 405 cuda_start(); 406 } 407 spin_unlock_irqrestore(&cuda_lock, flags); 408 409 return 0; 410 } 411 412 static void 413 cuda_start(void) 414 { 415 struct adb_request *req; 416 417 /* assert cuda_state == idle */ 418 /* get the packet to send */ 419 req = current_req; 420 if (req == 0) 421 return; 422 if ((in_8(&via[B]) & TREQ) == 0) 423 return; /* a byte is coming in from the CUDA */ 424 425 /* set the shift register to shift out and send a byte */ 426 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT); 427 out_8(&via[SR], req->data[0]); 428 out_8(&via[B], in_8(&via[B]) & ~TIP); 429 cuda_state = sent_first_byte; 430 } 431 432 void 433 cuda_poll(void) 434 { 435 /* cuda_interrupt only takes a normal lock, we disable 436 * interrupts here to avoid re-entering and thus deadlocking. 437 */ 438 if (cuda_irq) 439 disable_irq(cuda_irq); 440 cuda_interrupt(0, NULL); 441 if (cuda_irq) 442 enable_irq(cuda_irq); 443 } 444 445 static irqreturn_t 446 cuda_interrupt(int irq, void *arg) 447 { 448 int status; 449 struct adb_request *req = NULL; 450 unsigned char ibuf[16]; 451 int ibuf_len = 0; 452 int complete = 0; 453 454 spin_lock(&cuda_lock); 455 456 /* On powermacs, this handler is registered for the VIA IRQ. But they use 457 * just the shift register IRQ -- other VIA interrupt sources are disabled. 458 * On m68k macs, the VIA IRQ sources are dispatched individually. Unless 459 * we are polling, the shift register IRQ flag has already been cleared. 460 */ 461 462 #ifdef CONFIG_MAC 463 if (!arg) 464 #endif 465 { 466 if ((in_8(&via[IFR]) & SR_INT) == 0) { 467 spin_unlock(&cuda_lock); 468 return IRQ_NONE; 469 } else { 470 out_8(&via[IFR], SR_INT); 471 } 472 } 473 474 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT); 475 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */ 476 switch (cuda_state) { 477 case idle: 478 /* CUDA has sent us the first byte of data - unsolicited */ 479 if (status != TREQ) 480 printk("cuda: state=idle, 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 = cuda_rbuf; 485 reading_reply = 0; 486 break; 487 488 case awaiting_reply: 489 /* CUDA has sent us the first byte of data of a reply */ 490 if (status != TREQ) 491 printk("cuda: state=awaiting_reply, status=%x\n", status); 492 (void)in_8(&via[SR]); 493 out_8(&via[B], in_8(&via[B]) & ~TIP); 494 cuda_state = reading; 495 reply_ptr = current_req->reply; 496 reading_reply = 1; 497 break; 498 499 case sent_first_byte: 500 if (status == TREQ + TIP + SR_OUT) { 501 /* collision */ 502 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 503 (void)in_8(&via[SR]); 504 out_8(&via[B], in_8(&via[B]) | TIP | TACK); 505 cuda_state = idle; 506 } else { 507 /* assert status == TIP + SR_OUT */ 508 if (status != TIP + SR_OUT) 509 printk("cuda: state=sent_first_byte status=%x\n", status); 510 out_8(&via[SR], current_req->data[1]); 511 out_8(&via[B], in_8(&via[B]) ^ TACK); 512 data_index = 2; 513 cuda_state = sending; 514 } 515 break; 516 517 case sending: 518 req = current_req; 519 if (data_index >= req->nbytes) { 520 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 521 (void)in_8(&via[SR]); 522 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 523 req->sent = 1; 524 if (req->reply_expected) { 525 cuda_state = awaiting_reply; 526 } else { 527 current_req = req->next; 528 complete = 1; 529 /* not sure about this */ 530 cuda_state = idle; 531 cuda_start(); 532 } 533 } else { 534 out_8(&via[SR], req->data[data_index++]); 535 out_8(&via[B], in_8(&via[B]) ^ TACK); 536 } 537 break; 538 539 case reading: 540 *reply_ptr++ = in_8(&via[SR]); 541 if (status == TIP) { 542 /* that's all folks */ 543 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 544 cuda_state = read_done; 545 } else { 546 /* assert status == TIP | TREQ */ 547 if (status != TIP + TREQ) 548 printk("cuda: state=reading status=%x\n", status); 549 out_8(&via[B], in_8(&via[B]) ^ TACK); 550 } 551 break; 552 553 case read_done: 554 (void)in_8(&via[SR]); 555 if (reading_reply) { 556 req = current_req; 557 req->reply_len = reply_ptr - req->reply; 558 if (req->data[0] == ADB_PACKET) { 559 /* Have to adjust the reply from ADB commands */ 560 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) { 561 /* the 0x2 bit indicates no response */ 562 req->reply_len = 0; 563 } else { 564 /* leave just the command and result bytes in the reply */ 565 req->reply_len -= 2; 566 memmove(req->reply, req->reply + 2, req->reply_len); 567 } 568 } 569 current_req = req->next; 570 complete = 1; 571 } else { 572 /* This is tricky. We must break the spinlock to call 573 * cuda_input. However, doing so means we might get 574 * re-entered from another CPU getting an interrupt 575 * or calling cuda_poll(). I ended up using the stack 576 * (it's only for 16 bytes) and moving the actual 577 * call to cuda_input to outside of the lock. 578 */ 579 ibuf_len = reply_ptr - cuda_rbuf; 580 memcpy(ibuf, cuda_rbuf, ibuf_len); 581 } 582 if (status == TREQ) { 583 out_8(&via[B], in_8(&via[B]) & ~TIP); 584 cuda_state = reading; 585 reply_ptr = cuda_rbuf; 586 reading_reply = 0; 587 } else { 588 cuda_state = idle; 589 cuda_start(); 590 } 591 break; 592 593 default: 594 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state); 595 } 596 spin_unlock(&cuda_lock); 597 if (complete && req) { 598 void (*done)(struct adb_request *) = req->done; 599 mb(); 600 req->complete = 1; 601 /* Here, we assume that if the request has a done member, the 602 * struct request will survive to setting req->complete to 1 603 */ 604 if (done) 605 (*done)(req); 606 } 607 if (ibuf_len) 608 cuda_input(ibuf, ibuf_len); 609 return IRQ_HANDLED; 610 } 611 612 static void 613 cuda_input(unsigned char *buf, int nb) 614 { 615 int i; 616 617 switch (buf[0]) { 618 case ADB_PACKET: 619 #ifdef CONFIG_XMON 620 if (nb == 5 && buf[2] == 0x2c) { 621 extern int xmon_wants_key, xmon_adb_keycode; 622 if (xmon_wants_key) { 623 xmon_adb_keycode = buf[3]; 624 return; 625 } 626 } 627 #endif /* CONFIG_XMON */ 628 #ifdef CONFIG_ADB 629 adb_input(buf+2, nb-2, buf[1] & 0x40); 630 #endif /* CONFIG_ADB */ 631 break; 632 633 default: 634 printk("data from cuda (%d bytes):", nb); 635 for (i = 0; i < nb; ++i) 636 printk(" %.2x", buf[i]); 637 printk("\n"); 638 } 639 } 640