1 /* 2 * Device driver for the via ADB on (many) Mac II-class machines 3 * 4 * Based on the original ADB keyboard handler Copyright (c) 1997 Alan Cox 5 * Also derived from code Copyright (C) 1996 Paul Mackerras. 6 * 7 * With various updates provided over the years by Michael Schmitz, 8 * Guideo Koerber and others. 9 * 10 * Rewrite for Unified ADB by Joshua M. Thompson (funaho@jurai.org) 11 * 12 * 1999-08-02 (jmt) - Initial rewrite for Unified ADB. 13 * 2000-03-29 Tony Mantler <tonym@mac.linux-m68k.org> 14 * - Big overhaul, should actually work now. 15 */ 16 17 #include <stdarg.h> 18 #include <linux/types.h> 19 #include <linux/errno.h> 20 #include <linux/kernel.h> 21 #include <linux/delay.h> 22 #include <linux/sched.h> 23 #include <linux/adb.h> 24 #include <linux/interrupt.h> 25 #include <linux/init.h> 26 #include <asm/macintosh.h> 27 #include <asm/macints.h> 28 #include <asm/machw.h> 29 #include <asm/mac_via.h> 30 #include <asm/io.h> 31 #include <asm/system.h> 32 33 static volatile unsigned char *via; 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 #define ST_MASK 0x30 /* mask for selecting ADB state bits */ 59 60 /* Bits in ACR */ 61 #define SR_CTRL 0x1c /* Shift register control bits */ 62 #define SR_EXT 0x0c /* Shift on external clock */ 63 #define SR_OUT 0x10 /* Shift out if 1 */ 64 65 /* Bits in IFR and IER */ 66 #define IER_SET 0x80 /* set bits in IER */ 67 #define IER_CLR 0 /* clear bits in IER */ 68 #define SR_INT 0x04 /* Shift register full/empty */ 69 #define SR_DATA 0x08 /* Shift register data */ 70 #define SR_CLOCK 0x10 /* Shift register clock */ 71 72 /* ADB transaction states according to GMHW */ 73 #define ST_CMD 0x00 /* ADB state: command byte */ 74 #define ST_EVEN 0x10 /* ADB state: even data byte */ 75 #define ST_ODD 0x20 /* ADB state: odd data byte */ 76 #define ST_IDLE 0x30 /* ADB state: idle, nothing to send */ 77 78 static int macii_init_via(void); 79 static void macii_start(void); 80 static irqreturn_t macii_interrupt(int irq, void *arg, struct pt_regs *regs); 81 static void macii_retransmit(int); 82 static void macii_queue_poll(void); 83 84 static int macii_probe(void); 85 static int macii_init(void); 86 static int macii_send_request(struct adb_request *req, int sync); 87 static int macii_write(struct adb_request *req); 88 static int macii_autopoll(int devs); 89 static void macii_poll(void); 90 static int macii_reset_bus(void); 91 92 struct adb_driver via_macii_driver = { 93 "Mac II", 94 macii_probe, 95 macii_init, 96 macii_send_request, 97 macii_autopoll, 98 macii_poll, 99 macii_reset_bus 100 }; 101 102 static enum macii_state { 103 idle, 104 sending, 105 reading, 106 read_done, 107 awaiting_reply 108 } macii_state; 109 110 static int need_poll = 0; 111 static int command_byte = 0; 112 static int last_reply = 0; 113 static int last_active = 0; 114 115 static struct adb_request *current_req; 116 static struct adb_request *last_req; 117 static struct adb_request *retry_req; 118 static unsigned char reply_buf[16]; 119 static unsigned char *reply_ptr; 120 static int reply_len; 121 static int reading_reply; 122 static int data_index; 123 static int first_byte; 124 static int prefix_len; 125 static int status = ST_IDLE|TREQ; 126 static int last_status; 127 static int driver_running = 0; 128 129 /* debug level 10 required for ADB logging (should be && debug_adb, ideally) */ 130 131 /* Check for MacII style ADB */ 132 static int macii_probe(void) 133 { 134 if (macintosh_config->adb_type != MAC_ADB_II) return -ENODEV; 135 136 via = via1; 137 138 printk("adb: Mac II ADB Driver v1.0 for Unified ADB\n"); 139 return 0; 140 } 141 142 /* Initialize the driver */ 143 int macii_init(void) 144 { 145 unsigned long flags; 146 int err; 147 148 local_irq_save(flags); 149 150 err = macii_init_via(); 151 if (err) return err; 152 153 err = request_irq(IRQ_MAC_ADB, macii_interrupt, IRQ_FLG_LOCK, "ADB", 154 macii_interrupt); 155 if (err) return err; 156 157 macii_state = idle; 158 local_irq_restore(flags); 159 return 0; 160 } 161 162 /* initialize the hardware */ 163 static int macii_init_via(void) 164 { 165 unsigned char x; 166 167 /* Set the lines up. We want TREQ as input TACK|TIP as output */ 168 via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ; 169 170 /* Set up state: idle */ 171 via[B] |= ST_IDLE; 172 last_status = via[B] & (ST_MASK|TREQ); 173 174 /* Shift register on input */ 175 via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT; 176 177 /* Wipe any pending data and int */ 178 x = via[SR]; 179 180 return 0; 181 } 182 183 /* Send an ADB poll (Talk Register 0 command, tagged on the front of the request queue) */ 184 static void macii_queue_poll(void) 185 { 186 static int device = 0; 187 static int in_poll=0; 188 static struct adb_request req; 189 unsigned long flags; 190 191 if (in_poll) printk("macii_queue_poll: double poll!\n"); 192 193 in_poll++; 194 if (++device > 15) device = 1; 195 196 adb_request(&req, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1, 197 ADB_READREG(device, 0)); 198 199 local_irq_save(flags); 200 201 req.next = current_req; 202 current_req = &req; 203 204 local_irq_restore(flags); 205 macii_start(); 206 in_poll--; 207 } 208 209 /* Send an ADB retransmit (Talk, appended to the request queue) */ 210 static void macii_retransmit(int device) 211 { 212 static int in_retransmit = 0; 213 static struct adb_request rt; 214 unsigned long flags; 215 216 if (in_retransmit) printk("macii_retransmit: double retransmit!\n"); 217 218 in_retransmit++; 219 220 adb_request(&rt, NULL, ADBREQ_REPLY|ADBREQ_NOSEND, 1, 221 ADB_READREG(device, 0)); 222 223 local_irq_save(flags); 224 225 if (current_req != NULL) { 226 last_req->next = &rt; 227 last_req = &rt; 228 } else { 229 current_req = &rt; 230 last_req = &rt; 231 } 232 233 if (macii_state == idle) macii_start(); 234 235 local_irq_restore(flags); 236 in_retransmit--; 237 } 238 239 /* Send an ADB request; if sync, poll out the reply 'till it's done */ 240 static int macii_send_request(struct adb_request *req, int sync) 241 { 242 int i; 243 244 i = macii_write(req); 245 if (i) return i; 246 247 if (sync) { 248 while (!req->complete) macii_poll(); 249 } 250 return 0; 251 } 252 253 /* Send an ADB request */ 254 static int macii_write(struct adb_request *req) 255 { 256 unsigned long flags; 257 258 if (req->nbytes < 2 || req->data[0] != ADB_PACKET || req->nbytes > 15) { 259 req->complete = 1; 260 return -EINVAL; 261 } 262 263 req->next = NULL; 264 req->sent = 0; 265 req->complete = 0; 266 req->reply_len = 0; 267 268 local_irq_save(flags); 269 270 if (current_req != NULL) { 271 last_req->next = req; 272 last_req = req; 273 } else { 274 current_req = req; 275 last_req = req; 276 if (macii_state == idle) macii_start(); 277 } 278 279 local_irq_restore(flags); 280 return 0; 281 } 282 283 /* Start auto-polling */ 284 static int macii_autopoll(int devs) 285 { 286 /* Just ping a random default address */ 287 if (!(current_req || retry_req)) 288 macii_retransmit( (last_active < 16 && last_active > 0) ? last_active : 3); 289 return 0; 290 } 291 292 /* Prod the chip without interrupts */ 293 static void macii_poll(void) 294 { 295 unsigned long flags; 296 297 local_irq_save(flags); 298 if (via[IFR] & SR_INT) macii_interrupt(0, NULL, NULL); 299 local_irq_restore(flags); 300 } 301 302 /* Reset the bus */ 303 static int macii_reset_bus(void) 304 { 305 static struct adb_request req; 306 307 /* Command = 0, Address = ignored */ 308 adb_request(&req, NULL, 0, 1, ADB_BUSRESET); 309 310 return 0; 311 } 312 313 /* Start sending ADB packet */ 314 static void macii_start(void) 315 { 316 unsigned long flags; 317 struct adb_request *req; 318 319 req = current_req; 320 if (!req) return; 321 322 /* assert macii_state == idle */ 323 if (macii_state != idle) { 324 printk("macii_start: called while driver busy (%p %x %x)!\n", 325 req, macii_state, (uint) via1[B] & (ST_MASK|TREQ)); 326 return; 327 } 328 329 local_irq_save(flags); 330 331 /* 332 * IRQ signaled ?? (means ADB controller wants to send, or might 333 * be end of packet if we were reading) 334 */ 335 #if 0 /* FIXME: This is broke broke broke, for some reason */ 336 if ((via[B] & TREQ) == 0) { 337 printk("macii_start: weird poll stuff. huh?\n"); 338 /* 339 * FIXME - we need to restart this on a timer 340 * or a collision at boot hangs us. 341 * Never set macii_state to idle here, or macii_start 342 * won't be called again from send_request! 343 * (need to re-check other cases ...) 344 */ 345 /* 346 * if the interrupt handler set the need_poll 347 * flag, it's hopefully a SRQ poll or re-Talk 348 * so we try to send here anyway 349 */ 350 if (!need_poll) { 351 if (console_loglevel == 10) 352 printk("macii_start: device busy - retry %p state %d status %x!\n", 353 req, macii_state, 354 (uint) via[B] & (ST_MASK|TREQ)); 355 retry_req = req; 356 /* set ADB status here ? */ 357 local_irq_restore(flags); 358 return; 359 } else { 360 need_poll = 0; 361 } 362 } 363 #endif 364 /* 365 * Another retry pending? (sanity check) 366 */ 367 if (retry_req) { 368 retry_req = NULL; 369 } 370 371 /* Now send it. Be careful though, that first byte of the request */ 372 /* is actually ADB_PACKET; the real data begins at index 1! */ 373 374 /* store command byte */ 375 command_byte = req->data[1]; 376 /* Output mode */ 377 via[ACR] |= SR_OUT; 378 /* Load data */ 379 via[SR] = req->data[1]; 380 /* set ADB state to 'command' */ 381 via[B] = (via[B] & ~ST_MASK) | ST_CMD; 382 383 macii_state = sending; 384 data_index = 2; 385 386 local_irq_restore(flags); 387 } 388 389 /* 390 * The notorious ADB interrupt handler - does all of the protocol handling, 391 * except for starting new send operations. Relies heavily on the ADB 392 * controller sending and receiving data, thereby generating SR interrupts 393 * for us. This means there has to be always activity on the ADB bus, otherwise 394 * the whole process dies and has to be re-kicked by sending TALK requests ... 395 * CUDA-based Macs seem to solve this with the autopoll option, for MacII-type 396 * ADB the problem isn't solved yet (retransmit of the latest active TALK seems 397 * a good choice; either on timeout or on a timer interrupt). 398 * 399 * The basic ADB state machine was left unchanged from the original MacII code 400 * by Alan Cox, which was based on the CUDA driver for PowerMac. 401 * The syntax of the ADB status lines seems to be totally different on MacII, 402 * though. MacII uses the states Command -> Even -> Odd -> Even ->...-> Idle for 403 * sending, and Idle -> Even -> Odd -> Even ->...-> Idle for receiving. Start 404 * and end of a receive packet are signaled by asserting /IRQ on the interrupt 405 * line. Timeouts are signaled by a sequence of 4 0xFF, with /IRQ asserted on 406 * every other byte. SRQ is probably signaled by 3 or more 0xFF tacked on the 407 * end of a packet. (Thanks to Guido Koerber for eavesdropping on the ADB 408 * protocol with a logic analyzer!!) 409 * 410 * Note: As of 21/10/97, the MacII ADB part works including timeout detection 411 * and retransmit (Talk to the last active device). 412 */ 413 static irqreturn_t macii_interrupt(int irq, void *arg, struct pt_regs *regs) 414 { 415 int x, adbdir; 416 unsigned long flags; 417 struct adb_request *req; 418 419 last_status = status; 420 421 /* prevent races due to SCSI enabling ints */ 422 local_irq_save(flags); 423 424 if (driver_running) { 425 local_irq_restore(flags); 426 return IRQ_NONE; 427 } 428 429 driver_running = 1; 430 431 status = via[B] & (ST_MASK|TREQ); 432 adbdir = via[ACR] & SR_OUT; 433 434 switch (macii_state) { 435 case idle: 436 x = via[SR]; 437 first_byte = x; 438 /* set ADB state = even for first data byte */ 439 via[B] = (via[B] & ~ST_MASK) | ST_EVEN; 440 441 reply_buf[0] = first_byte; /* was command_byte?? */ 442 reply_ptr = reply_buf + 1; 443 reply_len = 1; 444 prefix_len = 1; 445 reading_reply = 0; 446 447 macii_state = reading; 448 break; 449 450 case awaiting_reply: 451 /* handshake etc. for II ?? */ 452 x = via[SR]; 453 first_byte = x; 454 /* set ADB state = even for first data byte */ 455 via[B] = (via[B] & ~ST_MASK) | ST_EVEN; 456 457 current_req->reply[0] = first_byte; 458 reply_ptr = current_req->reply + 1; 459 reply_len = 1; 460 prefix_len = 1; 461 reading_reply = 1; 462 463 macii_state = reading; 464 break; 465 466 case sending: 467 req = current_req; 468 if (data_index >= req->nbytes) { 469 /* print an error message if a listen command has no data */ 470 if (((command_byte & 0x0C) == 0x08) 471 /* && (console_loglevel == 10) */ 472 && (data_index == 2)) 473 printk("MacII ADB: listen command with no data: %x!\n", 474 command_byte); 475 /* reset to shift in */ 476 via[ACR] &= ~SR_OUT; 477 x = via[SR]; 478 /* set ADB state idle - might get SRQ */ 479 via[B] = (via[B] & ~ST_MASK) | ST_IDLE; 480 481 req->sent = 1; 482 483 if (req->reply_expected) { 484 macii_state = awaiting_reply; 485 } else { 486 req->complete = 1; 487 current_req = req->next; 488 if (req->done) (*req->done)(req); 489 macii_state = idle; 490 if (current_req || retry_req) 491 macii_start(); 492 else 493 macii_retransmit((command_byte & 0xF0) >> 4); 494 } 495 } else { 496 via[SR] = req->data[data_index++]; 497 498 if ( (via[B] & ST_MASK) == ST_CMD ) { 499 /* just sent the command byte, set to EVEN */ 500 via[B] = (via[B] & ~ST_MASK) | ST_EVEN; 501 } else { 502 /* invert state bits, toggle ODD/EVEN */ 503 via[B] ^= ST_MASK; 504 } 505 } 506 break; 507 508 case reading: 509 510 /* timeout / SRQ handling for II hw */ 511 if( (first_byte == 0xFF && (reply_len-prefix_len)==2 512 && memcmp(reply_ptr-2,"\xFF\xFF",2)==0) || 513 ((reply_len-prefix_len)==3 514 && memcmp(reply_ptr-3,"\xFF\xFF\xFF",3)==0)) 515 { 516 /* 517 * possible timeout (in fact, most probably a 518 * timeout, since SRQ can't be signaled without 519 * transfer on the bus). 520 * The last three bytes seen were FF, together 521 * with the starting byte (in case we started 522 * on 'idle' or 'awaiting_reply') this probably 523 * makes four. So this is mostl likely #5! 524 * The timeout signal is a pattern 1 0 1 0 0.. 525 * on /INT, meaning we missed it :-( 526 */ 527 x = via[SR]; 528 if (x != 0xFF) printk("MacII ADB: mistaken timeout/SRQ!\n"); 529 530 if ((status & TREQ) == (last_status & TREQ)) { 531 /* Not a timeout. Unsolicited SRQ? weird. */ 532 /* Terminate the SRQ packet and poll */ 533 need_poll = 1; 534 } 535 /* There's no packet to get, so reply is blank */ 536 via[B] ^= ST_MASK; 537 reply_ptr -= (reply_len-prefix_len); 538 reply_len = prefix_len; 539 macii_state = read_done; 540 break; 541 } /* end timeout / SRQ handling for II hw. */ 542 543 if((reply_len-prefix_len)>3 544 && memcmp(reply_ptr-3,"\xFF\xFF\xFF",3)==0) 545 { 546 /* SRQ tacked on data packet */ 547 /* Terminate the packet (SRQ never ends) */ 548 x = via[SR]; 549 macii_state = read_done; 550 reply_len -= 3; 551 reply_ptr -= 3; 552 need_poll = 1; 553 /* need to continue; next byte not seen else */ 554 } else { 555 /* Sanity check */ 556 if (reply_len > 15) reply_len = 0; 557 /* read byte */ 558 x = via[SR]; 559 *reply_ptr = x; 560 reply_ptr++; 561 reply_len++; 562 } 563 /* The usual handshake ... */ 564 565 /* 566 * NetBSD hints that the next to last byte 567 * is sent with IRQ !! 568 * Guido found out it's the last one (0x0), 569 * but IRQ should be asserted already. 570 * Problem with timeout detection: First 571 * transition to /IRQ might be second 572 * byte of timeout packet! 573 * Timeouts are signaled by 4x FF. 574 */ 575 if (((status & TREQ) == 0) && (x == 0x00)) { /* != 0xFF */ 576 /* invert state bits, toggle ODD/EVEN */ 577 via[B] ^= ST_MASK; 578 579 /* adjust packet length */ 580 reply_len--; 581 reply_ptr--; 582 macii_state = read_done; 583 } else { 584 /* not caught: ST_CMD */ 585 /* required for re-entry 'reading'! */ 586 if ((status & ST_MASK) == ST_IDLE) { 587 /* (in)sanity check - set even */ 588 via[B] = (via[B] & ~ST_MASK) | ST_EVEN; 589 } else { 590 /* invert state bits */ 591 via[B] ^= ST_MASK; 592 } 593 } 594 break; 595 596 case read_done: 597 x = via[SR]; 598 if (reading_reply) { 599 req = current_req; 600 req->reply_len = reply_ptr - req->reply; 601 req->complete = 1; 602 current_req = req->next; 603 if (req->done) (*req->done)(req); 604 } else { 605 adb_input(reply_buf, reply_ptr - reply_buf, 606 regs, 0); 607 } 608 609 /* 610 * remember this device ID; it's the latest we got a 611 * reply from! 612 */ 613 last_reply = command_byte; 614 last_active = (command_byte & 0xF0) >> 4; 615 616 /* SRQ seen before, initiate poll now */ 617 if (need_poll) { 618 macii_state = idle; 619 macii_queue_poll(); 620 need_poll = 0; 621 break; 622 } 623 624 /* set ADB state to idle */ 625 via[B] = (via[B] & ~ST_MASK) | ST_IDLE; 626 627 /* /IRQ seen, so the ADB controller has data for us */ 628 if ((via[B] & TREQ) != 0) { 629 macii_state = reading; 630 631 reply_buf[0] = command_byte; 632 reply_ptr = reply_buf + 1; 633 reply_len = 1; 634 prefix_len = 1; 635 reading_reply = 0; 636 } else { 637 /* no IRQ, send next packet or wait */ 638 macii_state = idle; 639 if (current_req) 640 macii_start(); 641 else 642 macii_retransmit(last_active); 643 } 644 break; 645 646 default: 647 break; 648 } 649 /* reset mutex and interrupts */ 650 driver_running = 0; 651 local_irq_restore(flags); 652 return IRQ_HANDLED; 653 } 654