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 <asm/system.h> 30#include <linux/init.h> 31 32static volatile unsigned char __iomem *via; 33static DEFINE_SPINLOCK(cuda_lock); 34 35/* VIA registers - spaced 0x200 bytes apart */ 36#define RS 0x200 /* skip between registers */ 37#define B 0 /* B-side data */ 38#define A RS /* A-side data */ 39#define DIRB (2*RS) /* B-side direction (1=output) */ 40#define DIRA (3*RS) /* A-side direction (1=output) */ 41#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 42#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 43#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 44#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 45#define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */ 46#define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */ 47#define SR (10*RS) /* Shift register */ 48#define ACR (11*RS) /* Auxiliary control register */ 49#define PCR (12*RS) /* Peripheral control register */ 50#define IFR (13*RS) /* Interrupt flag register */ 51#define IER (14*RS) /* Interrupt enable register */ 52#define ANH (15*RS) /* A-side data, no handshake */ 53 54/* Bits in B data register: all active low */ 55#define TREQ 0x08 /* Transfer request (input) */ 56#define TACK 0x10 /* Transfer acknowledge (output) */ 57#define TIP 0x20 /* Transfer in progress (output) */ 58 59/* Bits in ACR */ 60#define SR_CTRL 0x1c /* Shift register control bits */ 61#define SR_EXT 0x0c /* Shift on external clock */ 62#define SR_OUT 0x10 /* Shift out if 1 */ 63 64/* Bits in IFR and IER */ 65#define IER_SET 0x80 /* set bits in IER */ 66#define IER_CLR 0 /* clear bits in IER */ 67#define SR_INT 0x04 /* Shift register full/empty */ 68 69static enum cuda_state { 70 idle, 71 sent_first_byte, 72 sending, 73 reading, 74 read_done, 75 awaiting_reply 76} cuda_state; 77 78static struct adb_request *current_req; 79static struct adb_request *last_req; 80static unsigned char cuda_rbuf[16]; 81static unsigned char *reply_ptr; 82static int reading_reply; 83static int data_index; 84static int cuda_irq; 85#ifdef CONFIG_PPC 86static struct device_node *vias; 87#endif 88static int cuda_fully_inited; 89 90#ifdef CONFIG_ADB 91static int cuda_probe(void); 92static int cuda_send_request(struct adb_request *req, int sync); 93static int cuda_adb_autopoll(int devs); 94static int cuda_reset_adb_bus(void); 95#endif /* CONFIG_ADB */ 96 97static int cuda_init_via(void); 98static void cuda_start(void); 99static irqreturn_t cuda_interrupt(int irq, void *arg); 100static void cuda_input(unsigned char *buf, int nb); 101void cuda_poll(void); 102static int cuda_write(struct adb_request *req); 103 104int cuda_request(struct adb_request *req, 105 void (*done)(struct adb_request *), int nbytes, ...); 106 107#ifdef CONFIG_ADB 108struct adb_driver via_cuda_driver = { 109 .name = "CUDA", 110 .probe = cuda_probe, 111 .send_request = cuda_send_request, 112 .autopoll = cuda_adb_autopoll, 113 .poll = cuda_poll, 114 .reset_bus = cuda_reset_adb_bus, 115}; 116#endif /* CONFIG_ADB */ 117 118#ifdef CONFIG_MAC 119int __init find_via_cuda(void) 120{ 121 struct adb_request req; 122 int err; 123 124 if (macintosh_config->adb_type != MAC_ADB_CUDA) 125 return 0; 126 127 via = via1; 128 cuda_state = idle; 129 130 err = cuda_init_via(); 131 if (err) { 132 printk(KERN_ERR "cuda_init_via() failed\n"); 133 via = NULL; 134 return 0; 135 } 136 137 /* enable autopoll */ 138 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); 139 while (!req.complete) 140 cuda_poll(); 141 142 return 1; 143} 144#else 145int __init find_via_cuda(void) 146{ 147 struct adb_request req; 148 phys_addr_t taddr; 149 const u32 *reg; 150 int err; 151 152 if (vias != 0) 153 return 1; 154 vias = of_find_node_by_name(NULL, "via-cuda"); 155 if (vias == 0) 156 return 0; 157 158 reg = of_get_property(vias, "reg", NULL); 159 if (reg == NULL) { 160 printk(KERN_ERR "via-cuda: No \"reg\" property !\n"); 161 goto fail; 162 } 163 taddr = of_translate_address(vias, reg); 164 if (taddr == 0) { 165 printk(KERN_ERR "via-cuda: Can't translate address !\n"); 166 goto fail; 167 } 168 via = ioremap(taddr, 0x2000); 169 if (via == NULL) { 170 printk(KERN_ERR "via-cuda: Can't map address !\n"); 171 goto fail; 172 } 173 174 cuda_state = idle; 175 sys_ctrler = SYS_CTRLER_CUDA; 176 177 err = cuda_init_via(); 178 if (err) { 179 printk(KERN_ERR "cuda_init_via() failed\n"); 180 via = NULL; 181 return 0; 182 } 183 184 /* Clear and enable interrupts, but only on PPC. On 68K it's done */ 185 /* for us by the main VIA driver in arch/m68k/mac/via.c */ 186 187 out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */ 188 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */ 189 190 /* enable autopoll */ 191 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); 192 while (!req.complete) 193 cuda_poll(); 194 195 return 1; 196 197 fail: 198 of_node_put(vias); 199 vias = NULL; 200 return 0; 201} 202#endif /* !defined CONFIG_MAC */ 203 204static int __init via_cuda_start(void) 205{ 206 if (via == NULL) 207 return -ENODEV; 208 209#ifdef CONFIG_MAC 210 cuda_irq = IRQ_MAC_ADB; 211#else 212 cuda_irq = irq_of_parse_and_map(vias, 0); 213 if (cuda_irq == NO_IRQ) { 214 printk(KERN_ERR "via-cuda: can't map interrupts for %s\n", 215 vias->full_name); 216 return -ENODEV; 217 } 218#endif 219 220 if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) { 221 printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq); 222 return -EAGAIN; 223 } 224 225 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n"); 226 227 cuda_fully_inited = 1; 228 return 0; 229} 230 231device_initcall(via_cuda_start); 232 233#ifdef CONFIG_ADB 234static int 235cuda_probe(void) 236{ 237#ifdef CONFIG_PPC 238 if (sys_ctrler != SYS_CTRLER_CUDA) 239 return -ENODEV; 240#else 241 if (macintosh_config->adb_type != MAC_ADB_CUDA) 242 return -ENODEV; 243#endif 244 if (via == NULL) 245 return -ENODEV; 246 return 0; 247} 248#endif /* CONFIG_ADB */ 249 250#define WAIT_FOR(cond, what) \ 251 do { \ 252 int x; \ 253 for (x = 1000; !(cond); --x) { \ 254 if (x == 0) { \ 255 printk("Timeout waiting for " what "\n"); \ 256 return -ENXIO; \ 257 } \ 258 udelay(100); \ 259 } \ 260 } while (0) 261 262static int 263cuda_init_via(void) 264{ 265 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */ 266 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */ 267 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */ 268 (void)in_8(&via[SR]); /* clear any left-over data */ 269#ifdef CONFIG_PPC 270 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */ 271 (void)in_8(&via[IER]); 272#else 273 out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */ 274#endif 275 276 /* delay 4ms and then clear any pending interrupt */ 277 mdelay(4); 278 (void)in_8(&via[SR]); 279 out_8(&via[IFR], SR_INT); 280 281 /* sync with the CUDA - assert TACK without TIP */ 282 out_8(&via[B], in_8(&via[B]) & ~TACK); 283 284 /* wait for the CUDA to assert TREQ in response */ 285 WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync"); 286 287 /* wait for the interrupt and then clear it */ 288 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)"); 289 (void)in_8(&via[SR]); 290 out_8(&via[IFR], SR_INT); 291 292 /* finish the sync by negating TACK */ 293 out_8(&via[B], in_8(&via[B]) | TACK); 294 295 /* wait for the CUDA to negate TREQ and the corresponding interrupt */ 296 WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)"); 297 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)"); 298 (void)in_8(&via[SR]); 299 out_8(&via[IFR], SR_INT); 300 out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */ 301 302 return 0; 303} 304 305#ifdef CONFIG_ADB 306/* Send an ADB command */ 307static int 308cuda_send_request(struct adb_request *req, int sync) 309{ 310 int i; 311 312 if ((via == NULL) || !cuda_fully_inited) { 313 req->complete = 1; 314 return -ENXIO; 315 } 316 317 req->reply_expected = 1; 318 319 i = cuda_write(req); 320 if (i) 321 return i; 322 323 if (sync) { 324 while (!req->complete) 325 cuda_poll(); 326 } 327 return 0; 328} 329 330 331/* Enable/disable autopolling */ 332static int 333cuda_adb_autopoll(int devs) 334{ 335 struct adb_request req; 336 337 if ((via == NULL) || !cuda_fully_inited) 338 return -ENXIO; 339 340 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0)); 341 while (!req.complete) 342 cuda_poll(); 343 return 0; 344} 345 346/* Reset adb bus - how do we do this?? */ 347static int 348cuda_reset_adb_bus(void) 349{ 350 struct adb_request req; 351 352 if ((via == NULL) || !cuda_fully_inited) 353 return -ENXIO; 354 355 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */ 356 while (!req.complete) 357 cuda_poll(); 358 return 0; 359} 360#endif /* CONFIG_ADB */ 361/* Construct and send a cuda request */ 362int 363cuda_request(struct adb_request *req, void (*done)(struct adb_request *), 364 int nbytes, ...) 365{ 366 va_list list; 367 int i; 368 369 if (via == NULL) { 370 req->complete = 1; 371 return -ENXIO; 372 } 373 374 req->nbytes = nbytes; 375 req->done = done; 376 va_start(list, nbytes); 377 for (i = 0; i < nbytes; ++i) 378 req->data[i] = va_arg(list, int); 379 va_end(list); 380 req->reply_expected = 1; 381 return cuda_write(req); 382} 383 384static int 385cuda_write(struct adb_request *req) 386{ 387 unsigned long flags; 388 389 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) { 390 req->complete = 1; 391 return -EINVAL; 392 } 393 req->next = NULL; 394 req->sent = 0; 395 req->complete = 0; 396 req->reply_len = 0; 397 398 spin_lock_irqsave(&cuda_lock, flags); 399 if (current_req != 0) { 400 last_req->next = req; 401 last_req = req; 402 } else { 403 current_req = req; 404 last_req = req; 405 if (cuda_state == idle) 406 cuda_start(); 407 } 408 spin_unlock_irqrestore(&cuda_lock, flags); 409 410 return 0; 411} 412 413static void 414cuda_start(void) 415{ 416 struct adb_request *req; 417 418 /* assert cuda_state == idle */ 419 /* get the packet to send */ 420 req = current_req; 421 if (req == 0) 422 return; 423 if ((in_8(&via[B]) & TREQ) == 0) 424 return; /* a byte is coming in from the CUDA */ 425 426 /* set the shift register to shift out and send a byte */ 427 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT); 428 out_8(&via[SR], req->data[0]); 429 out_8(&via[B], in_8(&via[B]) & ~TIP); 430 cuda_state = sent_first_byte; 431} 432 433void 434cuda_poll(void) 435{ 436 /* cuda_interrupt only takes a normal lock, we disable 437 * interrupts here to avoid re-entering and thus deadlocking. 438 */ 439 if (cuda_irq) 440 disable_irq(cuda_irq); 441 cuda_interrupt(0, NULL); 442 if (cuda_irq) 443 enable_irq(cuda_irq); 444} 445 446static irqreturn_t 447cuda_interrupt(int irq, void *arg) 448{ 449 int status; 450 struct adb_request *req = NULL; 451 unsigned char ibuf[16]; 452 int ibuf_len = 0; 453 int complete = 0; 454 455 spin_lock(&cuda_lock); 456 457 /* On powermacs, this handler is registered for the VIA IRQ. But they use 458 * just the shift register IRQ -- other VIA interrupt sources are disabled. 459 * On m68k macs, the VIA IRQ sources are dispatched individually. Unless 460 * we are polling, the shift register IRQ flag has already been cleared. 461 */ 462 463#ifdef CONFIG_MAC 464 if (!arg) 465#endif 466 { 467 if ((in_8(&via[IFR]) & SR_INT) == 0) { 468 spin_unlock(&cuda_lock); 469 return IRQ_NONE; 470 } else { 471 out_8(&via[IFR], SR_INT); 472 } 473 } 474 475 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT); 476 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */ 477 switch (cuda_state) { 478 case idle: 479 /* CUDA has sent us the first byte of data - unsolicited */ 480 if (status != TREQ) 481 printk("cuda: state=idle, status=%x\n", status); 482 (void)in_8(&via[SR]); 483 out_8(&via[B], in_8(&via[B]) & ~TIP); 484 cuda_state = reading; 485 reply_ptr = cuda_rbuf; 486 reading_reply = 0; 487 break; 488 489 case awaiting_reply: 490 /* CUDA has sent us the first byte of data of a reply */ 491 if (status != TREQ) 492 printk("cuda: state=awaiting_reply, status=%x\n", status); 493 (void)in_8(&via[SR]); 494 out_8(&via[B], in_8(&via[B]) & ~TIP); 495 cuda_state = reading; 496 reply_ptr = current_req->reply; 497 reading_reply = 1; 498 break; 499 500 case sent_first_byte: 501 if (status == TREQ + TIP + SR_OUT) { 502 /* collision */ 503 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 504 (void)in_8(&via[SR]); 505 out_8(&via[B], in_8(&via[B]) | TIP | TACK); 506 cuda_state = idle; 507 } else { 508 /* assert status == TIP + SR_OUT */ 509 if (status != TIP + SR_OUT) 510 printk("cuda: state=sent_first_byte status=%x\n", status); 511 out_8(&via[SR], current_req->data[1]); 512 out_8(&via[B], in_8(&via[B]) ^ TACK); 513 data_index = 2; 514 cuda_state = sending; 515 } 516 break; 517 518 case sending: 519 req = current_req; 520 if (data_index >= req->nbytes) { 521 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); 522 (void)in_8(&via[SR]); 523 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 524 req->sent = 1; 525 if (req->reply_expected) { 526 cuda_state = awaiting_reply; 527 } else { 528 current_req = req->next; 529 complete = 1; 530 /* not sure about this */ 531 cuda_state = idle; 532 cuda_start(); 533 } 534 } else { 535 out_8(&via[SR], req->data[data_index++]); 536 out_8(&via[B], in_8(&via[B]) ^ TACK); 537 } 538 break; 539 540 case reading: 541 *reply_ptr++ = in_8(&via[SR]); 542 if (status == TIP) { 543 /* that's all folks */ 544 out_8(&via[B], in_8(&via[B]) | TACK | TIP); 545 cuda_state = read_done; 546 } else { 547 /* assert status == TIP | TREQ */ 548 if (status != TIP + TREQ) 549 printk("cuda: state=reading status=%x\n", status); 550 out_8(&via[B], in_8(&via[B]) ^ TACK); 551 } 552 break; 553 554 case read_done: 555 (void)in_8(&via[SR]); 556 if (reading_reply) { 557 req = current_req; 558 req->reply_len = reply_ptr - req->reply; 559 if (req->data[0] == ADB_PACKET) { 560 /* Have to adjust the reply from ADB commands */ 561 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) { 562 /* the 0x2 bit indicates no response */ 563 req->reply_len = 0; 564 } else { 565 /* leave just the command and result bytes in the reply */ 566 req->reply_len -= 2; 567 memmove(req->reply, req->reply + 2, req->reply_len); 568 } 569 } 570 current_req = req->next; 571 complete = 1; 572 } else { 573 /* This is tricky. We must break the spinlock to call 574 * cuda_input. However, doing so means we might get 575 * re-entered from another CPU getting an interrupt 576 * or calling cuda_poll(). I ended up using the stack 577 * (it's only for 16 bytes) and moving the actual 578 * call to cuda_input to outside of the lock. 579 */ 580 ibuf_len = reply_ptr - cuda_rbuf; 581 memcpy(ibuf, cuda_rbuf, ibuf_len); 582 } 583 if (status == TREQ) { 584 out_8(&via[B], in_8(&via[B]) & ~TIP); 585 cuda_state = reading; 586 reply_ptr = cuda_rbuf; 587 reading_reply = 0; 588 } else { 589 cuda_state = idle; 590 cuda_start(); 591 } 592 break; 593 594 default: 595 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state); 596 } 597 spin_unlock(&cuda_lock); 598 if (complete && req) { 599 void (*done)(struct adb_request *) = req->done; 600 mb(); 601 req->complete = 1; 602 /* Here, we assume that if the request has a done member, the 603 * struct request will survive to setting req->complete to 1 604 */ 605 if (done) 606 (*done)(req); 607 } 608 if (ibuf_len) 609 cuda_input(ibuf, ibuf_len); 610 return IRQ_HANDLED; 611} 612 613static void 614cuda_input(unsigned char *buf, int nb) 615{ 616 int i; 617 618 switch (buf[0]) { 619 case ADB_PACKET: 620#ifdef CONFIG_XMON 621 if (nb == 5 && buf[2] == 0x2c) { 622 extern int xmon_wants_key, xmon_adb_keycode; 623 if (xmon_wants_key) { 624 xmon_adb_keycode = buf[3]; 625 return; 626 } 627 } 628#endif /* CONFIG_XMON */ 629#ifdef CONFIG_ADB 630 adb_input(buf+2, nb-2, buf[1] & 0x40); 631#endif /* CONFIG_ADB */ 632 break; 633 634 default: 635 printk("data from cuda (%d bytes):", nb); 636 for (i = 0; i < nb; ++i) 637 printk(" %.2x", buf[i]); 638 printk("\n"); 639 } 640} 641