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