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 #ifdef CONFIG_PPC 197 request_OF_resource(vias, 0, NULL); 198 #endif 199 200 if (request_irq(CUDA_IRQ, cuda_interrupt, 0, "ADB", cuda_interrupt)) { 201 printk(KERN_ERR "cuda_init: can't get irq %d\n", CUDA_IRQ); 202 return -EAGAIN; 203 } 204 205 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n"); 206 207 cuda_fully_inited = 1; 208 return 0; 209 } 210 211 device_initcall(via_cuda_start); 212 213 #ifdef CONFIG_ADB 214 static int 215 cuda_probe(void) 216 { 217 #ifdef CONFIG_PPC 218 if (sys_ctrler != SYS_CTRLER_CUDA) 219 return -ENODEV; 220 #else 221 if (macintosh_config->adb_type != MAC_ADB_CUDA) 222 return -ENODEV; 223 via = via1; 224 #endif 225 return 0; 226 } 227 228 static int __init 229 cuda_init(void) 230 { 231 #ifdef CONFIG_PPC 232 if (via == NULL) 233 return -ENODEV; 234 return 0; 235 #else 236 int err = cuda_init_via(); 237 if (err) { 238 printk(KERN_ERR "cuda_init_via() failed\n"); 239 return -ENODEV; 240 } 241 242 return via_cuda_start(); 243 #endif 244 } 245 #endif /* CONFIG_ADB */ 246 247 #define WAIT_FOR(cond, what) \ 248 do { \ 249 int x; \ 250 for (x = 1000; !(cond); --x) { \ 251 if (x == 0) { \ 252 printk("Timeout waiting for " what "\n"); \ 253 return -ENXIO; \ 254 } \ 255 udelay(100); \ 256 } \ 257 } while (0) 258 259 static int 260 cuda_init_via(void) 261 { 262 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */ 263 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */ 264 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */ 265 (void)in_8(&via[SR]); /* clear any left-over data */ 266 #ifndef CONFIG_MAC 267 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */ 268 (void)in_8(&via[IER]); 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], in_8(&via[IFR]) & 0x7f); 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], in_8(&via[IFR]) & 0x7f); 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], in_8(&via[IFR]) & 0x7f); 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 unsigned long flags; 432 433 /* cuda_interrupt only takes a normal lock, we disable 434 * interrupts here to avoid re-entering and thus deadlocking. 435 * An option would be to disable only the IRQ source with 436 * disable_irq(), would that work on m68k ? --BenH 437 */ 438 local_irq_save(flags); 439 cuda_interrupt(0, NULL, NULL); 440 local_irq_restore(flags); 441 } 442 443 static irqreturn_t 444 cuda_interrupt(int irq, void *arg, struct pt_regs *regs) 445 { 446 int status; 447 struct adb_request *req = NULL; 448 unsigned char ibuf[16]; 449 int ibuf_len = 0; 450 int complete = 0; 451 unsigned char virq; 452 453 spin_lock(&cuda_lock); 454 455 virq = in_8(&via[IFR]) & 0x7f; 456 out_8(&via[IFR], virq); 457 if ((virq & SR_INT) == 0) { 458 spin_unlock(&cuda_lock); 459 return IRQ_NONE; 460 } 461 462 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT); 463 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */ 464 switch (cuda_state) { 465 case idle: 466 /* CUDA has sent us the first byte of data - unsolicited */ 467 if (status != TREQ) 468 printk("cuda: state=idle, status=%x\n", status); 469 (void)in_8(&via[SR]); 470 out_8(&via[B], in_8(&via[B]) & ~TIP); 471 cuda_state = reading; 472 reply_ptr = cuda_rbuf; 473 reading_reply = 0; 474 break; 475 476 case awaiting_reply: 477 /* CUDA has sent us the first byte of data of a reply */ 478 if (status != TREQ) 479 printk("cuda: state=awaiting_reply, status=%x\n", status); 480 (void)in_8(&via[SR]); 481 out_8(&via[B], in_8(&via[B]) & ~TIP); 482 cuda_state = reading; 483 reply_ptr = current_req->reply; 484 reading_reply = 1; 485 break; 486 487 case sent_first_byte: 488 if (status == TREQ + TIP + SR_OUT) { 489 /* collision */ 490 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 491 (void)in_8(&via[SR]); 492 out_8(&via[B], in_8(&via[B]) | TIP | TACK); 493 cuda_state = idle; 494 } else { 495 /* assert status == TIP + SR_OUT */ 496 if (status != TIP + SR_OUT) 497 printk("cuda: state=sent_first_byte status=%x\n", status); 498 out_8(&via[SR], current_req->data[1]); 499 out_8(&via[B], in_8(&via[B]) ^ TACK); 500 data_index = 2; 501 cuda_state = sending; 502 } 503 break; 504 505 case sending: 506 req = current_req; 507 if (data_index >= req->nbytes) { 508 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 509 (void)in_8(&via[SR]); 510 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 511 req->sent = 1; 512 if (req->reply_expected) { 513 cuda_state = awaiting_reply; 514 } else { 515 current_req = req->next; 516 complete = 1; 517 /* not sure about this */ 518 cuda_state = idle; 519 cuda_start(); 520 } 521 } else { 522 out_8(&via[SR], req->data[data_index++]); 523 out_8(&via[B], in_8(&via[B]) ^ TACK); 524 } 525 break; 526 527 case reading: 528 *reply_ptr++ = in_8(&via[SR]); 529 if (status == TIP) { 530 /* that's all folks */ 531 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 532 cuda_state = read_done; 533 } else { 534 /* assert status == TIP | TREQ */ 535 if (status != TIP + TREQ) 536 printk("cuda: state=reading status=%x\n", status); 537 out_8(&via[B], in_8(&via[B]) ^ TACK); 538 } 539 break; 540 541 case read_done: 542 (void)in_8(&via[SR]); 543 if (reading_reply) { 544 req = current_req; 545 req->reply_len = reply_ptr - req->reply; 546 if (req->data[0] == ADB_PACKET) { 547 /* Have to adjust the reply from ADB commands */ 548 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) { 549 /* the 0x2 bit indicates no response */ 550 req->reply_len = 0; 551 } else { 552 /* leave just the command and result bytes in the reply */ 553 req->reply_len -= 2; 554 memmove(req->reply, req->reply + 2, req->reply_len); 555 } 556 } 557 current_req = req->next; 558 complete = 1; 559 } else { 560 /* This is tricky. We must break the spinlock to call 561 * cuda_input. However, doing so means we might get 562 * re-entered from another CPU getting an interrupt 563 * or calling cuda_poll(). I ended up using the stack 564 * (it's only for 16 bytes) and moving the actual 565 * call to cuda_input to outside of the lock. 566 */ 567 ibuf_len = reply_ptr - cuda_rbuf; 568 memcpy(ibuf, cuda_rbuf, ibuf_len); 569 } 570 if (status == TREQ) { 571 out_8(&via[B], in_8(&via[B]) & ~TIP); 572 cuda_state = reading; 573 reply_ptr = cuda_rbuf; 574 reading_reply = 0; 575 } else { 576 cuda_state = idle; 577 cuda_start(); 578 } 579 break; 580 581 default: 582 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state); 583 } 584 spin_unlock(&cuda_lock); 585 if (complete && req) { 586 void (*done)(struct adb_request *) = req->done; 587 mb(); 588 req->complete = 1; 589 /* Here, we assume that if the request has a done member, the 590 * struct request will survive to setting req->complete to 1 591 */ 592 if (done) 593 (*done)(req); 594 } 595 if (ibuf_len) 596 cuda_input(ibuf, ibuf_len, regs); 597 return IRQ_HANDLED; 598 } 599 600 static void 601 cuda_input(unsigned char *buf, int nb, struct pt_regs *regs) 602 { 603 int i; 604 605 switch (buf[0]) { 606 case ADB_PACKET: 607 #ifdef CONFIG_XMON 608 if (nb == 5 && buf[2] == 0x2c) { 609 extern int xmon_wants_key, xmon_adb_keycode; 610 if (xmon_wants_key) { 611 xmon_adb_keycode = buf[3]; 612 return; 613 } 614 } 615 #endif /* CONFIG_XMON */ 616 #ifdef CONFIG_ADB 617 adb_input(buf+2, nb-2, regs, buf[1] & 0x40); 618 #endif /* CONFIG_ADB */ 619 break; 620 621 default: 622 printk("data from cuda (%d bytes):", nb); 623 for (i = 0; i < nb; ++i) 624 printk(" %.2x", buf[i]); 625 printk("\n"); 626 } 627 } 628