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 if (request_irq(CUDA_IRQ, cuda_interrupt, 0, "ADB", cuda_interrupt)) { 197 printk(KERN_ERR "cuda_init: can't get irq %d\n", CUDA_IRQ); 198 return -EAGAIN; 199 } 200 201 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n"); 202 203 cuda_fully_inited = 1; 204 return 0; 205 } 206 207 device_initcall(via_cuda_start); 208 209 #ifdef CONFIG_ADB 210 static int 211 cuda_probe(void) 212 { 213 #ifdef CONFIG_PPC 214 if (sys_ctrler != SYS_CTRLER_CUDA) 215 return -ENODEV; 216 #else 217 if (macintosh_config->adb_type != MAC_ADB_CUDA) 218 return -ENODEV; 219 via = via1; 220 #endif 221 return 0; 222 } 223 224 static int __init 225 cuda_init(void) 226 { 227 #ifdef CONFIG_PPC 228 if (via == NULL) 229 return -ENODEV; 230 return 0; 231 #else 232 int err = cuda_init_via(); 233 if (err) { 234 printk(KERN_ERR "cuda_init_via() failed\n"); 235 return -ENODEV; 236 } 237 238 return via_cuda_start(); 239 #endif 240 } 241 #endif /* CONFIG_ADB */ 242 243 #define WAIT_FOR(cond, what) \ 244 do { \ 245 int x; \ 246 for (x = 1000; !(cond); --x) { \ 247 if (x == 0) { \ 248 printk("Timeout waiting for " what "\n"); \ 249 return -ENXIO; \ 250 } \ 251 udelay(100); \ 252 } \ 253 } while (0) 254 255 static int 256 cuda_init_via(void) 257 { 258 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */ 259 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */ 260 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */ 261 (void)in_8(&via[SR]); /* clear any left-over data */ 262 #ifndef CONFIG_MAC 263 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */ 264 (void)in_8(&via[IER]); 265 #endif 266 267 /* delay 4ms and then clear any pending interrupt */ 268 mdelay(4); 269 (void)in_8(&via[SR]); 270 out_8(&via[IFR], in_8(&via[IFR]) & 0x7f); 271 272 /* sync with the CUDA - assert TACK without TIP */ 273 out_8(&via[B], in_8(&via[B]) & ~TACK); 274 275 /* wait for the CUDA to assert TREQ in response */ 276 WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync"); 277 278 /* wait for the interrupt and then clear it */ 279 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)"); 280 (void)in_8(&via[SR]); 281 out_8(&via[IFR], in_8(&via[IFR]) & 0x7f); 282 283 /* finish the sync by negating TACK */ 284 out_8(&via[B], in_8(&via[B]) | TACK); 285 286 /* wait for the CUDA to negate TREQ and the corresponding interrupt */ 287 WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)"); 288 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)"); 289 (void)in_8(&via[SR]); 290 out_8(&via[IFR], in_8(&via[IFR]) & 0x7f); 291 out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */ 292 293 return 0; 294 } 295 296 #ifdef CONFIG_ADB 297 /* Send an ADB command */ 298 static int 299 cuda_send_request(struct adb_request *req, int sync) 300 { 301 int i; 302 303 if ((via == NULL) || !cuda_fully_inited) { 304 req->complete = 1; 305 return -ENXIO; 306 } 307 308 req->reply_expected = 1; 309 310 i = cuda_write(req); 311 if (i) 312 return i; 313 314 if (sync) { 315 while (!req->complete) 316 cuda_poll(); 317 } 318 return 0; 319 } 320 321 322 /* Enable/disable autopolling */ 323 static int 324 cuda_adb_autopoll(int devs) 325 { 326 struct adb_request req; 327 328 if ((via == NULL) || !cuda_fully_inited) 329 return -ENXIO; 330 331 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0)); 332 while (!req.complete) 333 cuda_poll(); 334 return 0; 335 } 336 337 /* Reset adb bus - how do we do this?? */ 338 static int 339 cuda_reset_adb_bus(void) 340 { 341 struct adb_request req; 342 343 if ((via == NULL) || !cuda_fully_inited) 344 return -ENXIO; 345 346 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */ 347 while (!req.complete) 348 cuda_poll(); 349 return 0; 350 } 351 #endif /* CONFIG_ADB */ 352 /* Construct and send a cuda request */ 353 int 354 cuda_request(struct adb_request *req, void (*done)(struct adb_request *), 355 int nbytes, ...) 356 { 357 va_list list; 358 int i; 359 360 if (via == NULL) { 361 req->complete = 1; 362 return -ENXIO; 363 } 364 365 req->nbytes = nbytes; 366 req->done = done; 367 va_start(list, nbytes); 368 for (i = 0; i < nbytes; ++i) 369 req->data[i] = va_arg(list, int); 370 va_end(list); 371 req->reply_expected = 1; 372 return cuda_write(req); 373 } 374 375 static int 376 cuda_write(struct adb_request *req) 377 { 378 unsigned long flags; 379 380 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) { 381 req->complete = 1; 382 return -EINVAL; 383 } 384 req->next = NULL; 385 req->sent = 0; 386 req->complete = 0; 387 req->reply_len = 0; 388 389 spin_lock_irqsave(&cuda_lock, flags); 390 if (current_req != 0) { 391 last_req->next = req; 392 last_req = req; 393 } else { 394 current_req = req; 395 last_req = req; 396 if (cuda_state == idle) 397 cuda_start(); 398 } 399 spin_unlock_irqrestore(&cuda_lock, flags); 400 401 return 0; 402 } 403 404 static void 405 cuda_start(void) 406 { 407 struct adb_request *req; 408 409 /* assert cuda_state == idle */ 410 /* get the packet to send */ 411 req = current_req; 412 if (req == 0) 413 return; 414 if ((in_8(&via[B]) & TREQ) == 0) 415 return; /* a byte is coming in from the CUDA */ 416 417 /* set the shift register to shift out and send a byte */ 418 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT); 419 out_8(&via[SR], req->data[0]); 420 out_8(&via[B], in_8(&via[B]) & ~TIP); 421 cuda_state = sent_first_byte; 422 } 423 424 void 425 cuda_poll(void) 426 { 427 unsigned long flags; 428 429 /* cuda_interrupt only takes a normal lock, we disable 430 * interrupts here to avoid re-entering and thus deadlocking. 431 * An option would be to disable only the IRQ source with 432 * disable_irq(), would that work on m68k ? --BenH 433 */ 434 local_irq_save(flags); 435 cuda_interrupt(0, NULL, NULL); 436 local_irq_restore(flags); 437 } 438 439 static irqreturn_t 440 cuda_interrupt(int irq, void *arg, struct pt_regs *regs) 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 unsigned char virq; 448 449 spin_lock(&cuda_lock); 450 451 virq = in_8(&via[IFR]) & 0x7f; 452 out_8(&via[IFR], virq); 453 if ((virq & SR_INT) == 0) { 454 spin_unlock(&cuda_lock); 455 return IRQ_NONE; 456 } 457 458 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT); 459 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */ 460 switch (cuda_state) { 461 case idle: 462 /* CUDA has sent us the first byte of data - unsolicited */ 463 if (status != TREQ) 464 printk("cuda: state=idle, status=%x\n", status); 465 (void)in_8(&via[SR]); 466 out_8(&via[B], in_8(&via[B]) & ~TIP); 467 cuda_state = reading; 468 reply_ptr = cuda_rbuf; 469 reading_reply = 0; 470 break; 471 472 case awaiting_reply: 473 /* CUDA has sent us the first byte of data of a reply */ 474 if (status != TREQ) 475 printk("cuda: state=awaiting_reply, status=%x\n", status); 476 (void)in_8(&via[SR]); 477 out_8(&via[B], in_8(&via[B]) & ~TIP); 478 cuda_state = reading; 479 reply_ptr = current_req->reply; 480 reading_reply = 1; 481 break; 482 483 case sent_first_byte: 484 if (status == TREQ + TIP + SR_OUT) { 485 /* collision */ 486 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 487 (void)in_8(&via[SR]); 488 out_8(&via[B], in_8(&via[B]) | TIP | TACK); 489 cuda_state = idle; 490 } else { 491 /* assert status == TIP + SR_OUT */ 492 if (status != TIP + SR_OUT) 493 printk("cuda: state=sent_first_byte status=%x\n", status); 494 out_8(&via[SR], current_req->data[1]); 495 out_8(&via[B], in_8(&via[B]) ^ TACK); 496 data_index = 2; 497 cuda_state = sending; 498 } 499 break; 500 501 case sending: 502 req = current_req; 503 if (data_index >= req->nbytes) { 504 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 505 (void)in_8(&via[SR]); 506 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 507 req->sent = 1; 508 if (req->reply_expected) { 509 cuda_state = awaiting_reply; 510 } else { 511 current_req = req->next; 512 complete = 1; 513 /* not sure about this */ 514 cuda_state = idle; 515 cuda_start(); 516 } 517 } else { 518 out_8(&via[SR], req->data[data_index++]); 519 out_8(&via[B], in_8(&via[B]) ^ TACK); 520 } 521 break; 522 523 case reading: 524 *reply_ptr++ = in_8(&via[SR]); 525 if (status == TIP) { 526 /* that's all folks */ 527 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 528 cuda_state = read_done; 529 } else { 530 /* assert status == TIP | TREQ */ 531 if (status != TIP + TREQ) 532 printk("cuda: state=reading status=%x\n", status); 533 out_8(&via[B], in_8(&via[B]) ^ TACK); 534 } 535 break; 536 537 case read_done: 538 (void)in_8(&via[SR]); 539 if (reading_reply) { 540 req = current_req; 541 req->reply_len = reply_ptr - req->reply; 542 if (req->data[0] == ADB_PACKET) { 543 /* Have to adjust the reply from ADB commands */ 544 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) { 545 /* the 0x2 bit indicates no response */ 546 req->reply_len = 0; 547 } else { 548 /* leave just the command and result bytes in the reply */ 549 req->reply_len -= 2; 550 memmove(req->reply, req->reply + 2, req->reply_len); 551 } 552 } 553 current_req = req->next; 554 complete = 1; 555 } else { 556 /* This is tricky. We must break the spinlock to call 557 * cuda_input. However, doing so means we might get 558 * re-entered from another CPU getting an interrupt 559 * or calling cuda_poll(). I ended up using the stack 560 * (it's only for 16 bytes) and moving the actual 561 * call to cuda_input to outside of the lock. 562 */ 563 ibuf_len = reply_ptr - cuda_rbuf; 564 memcpy(ibuf, cuda_rbuf, ibuf_len); 565 } 566 if (status == TREQ) { 567 out_8(&via[B], in_8(&via[B]) & ~TIP); 568 cuda_state = reading; 569 reply_ptr = cuda_rbuf; 570 reading_reply = 0; 571 } else { 572 cuda_state = idle; 573 cuda_start(); 574 } 575 break; 576 577 default: 578 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state); 579 } 580 spin_unlock(&cuda_lock); 581 if (complete && req) { 582 void (*done)(struct adb_request *) = req->done; 583 mb(); 584 req->complete = 1; 585 /* Here, we assume that if the request has a done member, the 586 * struct request will survive to setting req->complete to 1 587 */ 588 if (done) 589 (*done)(req); 590 } 591 if (ibuf_len) 592 cuda_input(ibuf, ibuf_len, regs); 593 return IRQ_HANDLED; 594 } 595 596 static void 597 cuda_input(unsigned char *buf, int nb, struct pt_regs *regs) 598 { 599 int i; 600 601 switch (buf[0]) { 602 case ADB_PACKET: 603 #ifdef CONFIG_XMON 604 if (nb == 5 && buf[2] == 0x2c) { 605 extern int xmon_wants_key, xmon_adb_keycode; 606 if (xmon_wants_key) { 607 xmon_adb_keycode = buf[3]; 608 return; 609 } 610 } 611 #endif /* CONFIG_XMON */ 612 #ifdef CONFIG_ADB 613 adb_input(buf+2, nb-2, regs, buf[1] & 0x40); 614 #endif /* CONFIG_ADB */ 615 break; 616 617 default: 618 printk("data from cuda (%d bytes):", nb); 619 for (i = 0; i < nb; ++i) 620 printk(" %.2x", buf[i]); 621 printk("\n"); 622 } 623 } 624