via-maciisi.c 15.4 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
/*
 * Device driver for the IIsi-style ADB on some Mac LC and II-class machines
 *
 * Based on via-cuda.c and via-macii.c, as well as the original
 * adb-bus.c, which in turn is somewhat influenced by (but uses no
 * code from) the NetBSD HWDIRECT ADB code.  Original IIsi driver work
 * was done by Robert Thompson and integrated into the old style
 * driver by Michael Schmitz.
 *
 * Original sources (c) Alan Cox, Paul Mackerras, and others.
 *
 * Rewritten for Unified ADB by David Huggins-Daines <dhd@debian.org>
 * 
 * 7/13/2000- extensive changes by Andrew McPherson <andrew@macduff.dhs.org>
 * Works about 30% of the time now.
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_via.h>

static volatile unsigned char *via;

/* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
#define RS		0x200		/* skip between registers */
#define B		0		/* B-side data */
#define A		RS		/* A-side data */
#define DIRB		(2*RS)		/* B-side direction (1=output) */
#define DIRA		(3*RS)		/* A-side direction (1=output) */
#define SR		(10*RS)		/* Shift register */
#define ACR		(11*RS)		/* Auxiliary control register */
#define IFR		(13*RS)		/* Interrupt flag register */
#define IER		(14*RS)		/* Interrupt enable register */

/* Bits in B data register: all active low */
#define TREQ		0x08		/* Transfer request (input) */
#define TACK		0x10		/* Transfer acknowledge (output) */
#define TIP		0x20		/* Transfer in progress (output) */
#define ST_MASK		0x30		/* mask for selecting ADB state bits */

/* Bits in ACR */
#define SR_CTRL		0x1c		/* Shift register control bits */
#define SR_EXT		0x0c		/* Shift on external clock */
#define SR_OUT		0x10		/* Shift out if 1 */

/* Bits in IFR and IER */
#define IER_SET		0x80		/* set bits in IER */
#define IER_CLR		0		/* clear bits in IER */
#define SR_INT		0x04		/* Shift register full/empty */
#define SR_DATA		0x08		/* Shift register data */
#define SR_CLOCK	0x10		/* Shift register clock */

#define ADB_DELAY 150

#undef DEBUG_MACIISI_ADB

static struct adb_request* current_req;
static struct adb_request* last_req;
static unsigned char maciisi_rbuf[16];
static unsigned char *reply_ptr;
static int data_index;
static int reading_reply;
static int reply_len;
static int tmp;
static int need_sync;

static enum maciisi_state {
    idle,
    sending,
    reading,
} maciisi_state;

static int maciisi_probe(void);
static int maciisi_init(void);
static int maciisi_send_request(struct adb_request* req, int sync);
static void maciisi_sync(struct adb_request *req);
static int maciisi_write(struct adb_request* req);
static irqreturn_t maciisi_interrupt(int irq, void* arg);
static void maciisi_input(unsigned char *buf, int nb);
static int maciisi_init_via(void);
static void maciisi_poll(void);
static int maciisi_start(void);

struct adb_driver via_maciisi_driver = {
	"Mac IIsi",
	maciisi_probe,
	maciisi_init,
	maciisi_send_request,
	NULL, /* maciisi_adb_autopoll, */
	maciisi_poll,
	NULL /* maciisi_reset_adb_bus */
};

static int
maciisi_probe(void)
{
	if (macintosh_config->adb_type != MAC_ADB_IISI)
		return -ENODEV;

	via = via1;
	return 0;
}

static int
maciisi_init(void)
{
	int err;

	if (via == NULL)
		return -ENODEV;

	if ((err = maciisi_init_via())) {
		printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
		via = NULL;
		return err;
	}

	if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK | IRQ_FLG_FAST, 
			"ADB", maciisi_interrupt)) {
		printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
		return -EAGAIN;
	}

	printk("adb: Mac IIsi driver v0.2 for Unified ADB.\n");
	return 0;
}

/* Flush data from the ADB controller */
static void
maciisi_stfu(void)
{
	int status = via[B] & (TIP|TREQ);

	if (status & TREQ) {
#ifdef DEBUG_MACIISI_ADB
		printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
#endif
		return;
	}
	
	udelay(ADB_DELAY);
	via[ACR] &= ~SR_OUT;
	via[IER] = IER_CLR | SR_INT;

	udelay(ADB_DELAY);

	status = via[B] & (TIP|TREQ);

	if (!(status & TREQ))
	{
		via[B] |= TIP;

		while(1)
		{
			int poll_timeout = ADB_DELAY * 5;
			/* Poll for SR interrupt */
			while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
				status = via[B] & (TIP|TREQ);

			tmp = via[SR]; /* Clear shift register */
#ifdef DEBUG_MACIISI_ADB
			printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d data %x\n",
			       status, poll_timeout, tmp);
#endif	
			if(via[B] & TREQ)
				break;
	
			/* ACK on-off */
			via[B] |= TACK;
			udelay(ADB_DELAY);
			via[B] &= ~TACK;
		}

		/* end frame */
		via[B] &= ~TIP;
		udelay(ADB_DELAY);
	}

	via[IER] = IER_SET | SR_INT;	
}

/* All specifically VIA-related initialization goes here */
static int
maciisi_init_via(void)
{
	int	i;
	
	/* Set the lines up. We want TREQ as input TACK|TIP as output */
	via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
	/* Shift register on input */
	via[ACR]  = (via[ACR] & ~SR_CTRL) | SR_EXT;
#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
#endif
	/* Wipe any pending data and int */
	tmp = via[SR];
	/* Enable keyboard interrupts */
	via[IER] = IER_SET | SR_INT;
	/* Set initial state: idle */
	via[B] &= ~(TACK|TIP);
	/* Clear interrupt bit */
	via[IFR] = SR_INT;

	for(i = 0; i < 60; i++) {
		udelay(ADB_DELAY);
		maciisi_stfu();
		udelay(ADB_DELAY);
		if(via[B] & TREQ)
			break;
	}
	if (i == 60)
		printk(KERN_ERR "maciisi_init_via: bus jam?\n");

	maciisi_state = idle;
	need_sync = 0;

	return 0;
}

/* Send a request, possibly waiting for a reply */
static int
maciisi_send_request(struct adb_request* req, int sync)
{
	int i;

#ifdef DEBUG_MACIISI_ADB
	static int dump_packet = 0;
#endif

	if (via == NULL) {
		req->complete = 1;
		return -ENXIO;
	}

#ifdef DEBUG_MACIISI_ADB
	if (dump_packet) {
		printk(KERN_DEBUG "maciisi_send_request:");
		for (i = 0; i < req->nbytes; i++) {
			printk(" %.2x", req->data[i]);
		}
		printk(" sync %d\n", sync);
	}
#endif

	req->reply_expected = 1;
	
	i = maciisi_write(req);
	if (i)
	{
		/* Normally, if a packet requires syncing, that happens at the end of
		 * maciisi_send_request. But if the transfer fails, it will be restarted
		 * by maciisi_interrupt(). We use need_sync to tell maciisi_interrupt
		 * when to sync a packet that it sends out.
		 * 
		 * Suggestions on a better way to do this are welcome.
		 */
		if(i == -EBUSY && sync)
			need_sync = 1;
		else
			need_sync = 0;
		return i;
	}
	if(sync)
		maciisi_sync(req);
	
	return 0;
}

/* Poll the ADB chip until the request completes */
static void maciisi_sync(struct adb_request *req)
{
	int count = 0; 

#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "maciisi_sync called\n");
#endif

	/* If for some reason the ADB chip shuts up on us, we want to avoid an endless loop. */
	while (!req->complete && count++ < 50) {
		maciisi_poll();
	}
	/* This could be BAD... when the ADB controller doesn't respond
	 * for this long, it's probably not coming back :-( */
	if(count >= 50) /* Hopefully shouldn't happen */
		printk(KERN_ERR "maciisi_send_request: poll timed out!\n");
}

int
maciisi_request(struct adb_request *req, void (*done)(struct adb_request *),
	    int nbytes, ...)
{
	va_list list;
	int i;

	req->nbytes = nbytes;
	req->done = done;
	req->reply_expected = 0;
	va_start(list, nbytes);
	for (i = 0; i < nbytes; i++)
		req->data[i++] = va_arg(list, int);
	va_end(list);

	return maciisi_send_request(req, 1);
}

/* Enqueue a request, and run the queue if possible */
static int
maciisi_write(struct adb_request* req)
{
	unsigned long flags;
	int i;

	/* We will accept CUDA packets - the VIA sends them to us, so
           it figures that we should be able to send them to it */
	if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
		printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
		req->complete = 1;
		return -EINVAL;
	}
	req->next = NULL;
	req->sent = 0;
	req->complete = 0;
	req->reply_len = 0;
	
	local_irq_save(flags);

	if (current_req) {
		last_req->next = req;
		last_req = req;
	} else {
		current_req = req;
		last_req = req;
	}
	if (maciisi_state == idle)
	{
		i = maciisi_start();
		if(i != 0)
		{
			local_irq_restore(flags);
			return i;
		}
	}
	else
	{
#ifdef DEBUG_MACIISI_ADB
		printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
#endif
		local_irq_restore(flags);
		return -EBUSY;
	}

	local_irq_restore(flags);

	return 0;
}

static int
maciisi_start(void)
{
	struct adb_request* req;
	int status;

#ifdef DEBUG_MACIISI_ADB
	status = via[B] & (TIP | TREQ);

	printk(KERN_DEBUG "maciisi_start called, state=%d, status=%x, ifr=%x\n", maciisi_state, status, via[IFR]);
#endif

	if (maciisi_state != idle) {
		/* shouldn't happen */
		printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
		return -EBUSY;
	}

	req = current_req;
	if (req == NULL)
		return -EINVAL;

	status = via[B] & (TIP|TREQ);
	if (!(status & TREQ)) {
#ifdef DEBUG_MACIISI_ADB
		printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
#endif
		return -EBUSY;
	}

	/* Okay, send */
#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "maciisi_start: sending\n");
#endif
	/* Set state to active */
	via[B] |= TIP;
	/* ACK off */
	via[B] &= ~TACK;
	/* Delay */
	udelay(ADB_DELAY);
	/* Shift out and send */
	via[ACR] |= SR_OUT;
	via[SR] = req->data[0];
	data_index = 1;
	/* ACK on */
	via[B] |= TACK;
	maciisi_state = sending;

	return 0;
}

void
maciisi_poll(void)
{
	unsigned long flags;

	local_irq_save(flags);
	if (via[IFR] & SR_INT) {
		maciisi_interrupt(0, NULL);
	}
	else /* avoid calling this function too quickly in a loop */
		udelay(ADB_DELAY);

	local_irq_restore(flags);
}

/* Shift register interrupt - this is *supposed* to mean that the
   register is either full or empty. In practice, I have no idea what
   it means :( */
static irqreturn_t
maciisi_interrupt(int irq, void* arg)
{
	int status;
	struct adb_request *req;
#ifdef DEBUG_MACIISI_ADB
	static int dump_reply = 0;
#endif
	int i;
	unsigned long flags;

	local_irq_save(flags);

	status = via[B] & (TIP|TREQ);
#ifdef DEBUG_MACIISI_ADB
	printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
#endif

	if (!(via[IFR] & SR_INT)) {
		/* Shouldn't happen, we hope */
		printk(KERN_ERR "maciisi_interrupt: called without interrupt flag set\n");
		local_irq_restore(flags);
		return IRQ_NONE;
	}

	/* Clear the interrupt */
	/* via[IFR] = SR_INT; */

 switch_start:
	switch (maciisi_state) {
	case idle:
		if (status & TIP)
			printk(KERN_ERR "maciisi_interrupt: state is idle but TIP asserted!\n");

		if(!reading_reply)
			udelay(ADB_DELAY);
		/* Shift in */
		via[ACR] &= ~SR_OUT;
 		/* Signal start of frame */
		via[B] |= TIP;
		/* Clear the interrupt (throw this value on the floor, it's useless) */
		tmp = via[SR];
		/* ACK adb chip, high-low */
		via[B] |= TACK;
		udelay(ADB_DELAY);
		via[B] &= ~TACK;
		reply_len = 0;
		maciisi_state = reading;
		if (reading_reply) {
			reply_ptr = current_req->reply;
		} else {
			reply_ptr = maciisi_rbuf;
		}
		break;

	case sending:
		/* via[SR]; */
		/* Set ACK off */
		via[B] &= ~TACK;
		req = current_req;

		if (!(status & TREQ)) {
			/* collision */
			printk(KERN_ERR "maciisi_interrupt: send collision\n");
			/* Set idle and input */
			via[ACR] &= ~SR_OUT;
			tmp = via[SR];
			via[B] &= ~TIP;
			/* Must re-send */
			reading_reply = 0;
			reply_len = 0;
			maciisi_state = idle;
			udelay(ADB_DELAY);
			/* process this now, because the IFR has been cleared */
			goto switch_start;
		}

		udelay(ADB_DELAY);

		if (data_index >= req->nbytes) {
			/* Sent the whole packet, put the bus back in idle state */
			/* Shift in, we are about to read a reply (hopefully) */
			via[ACR] &= ~SR_OUT;
			tmp = via[SR];
			/* End of frame */
			via[B] &= ~TIP;
			req->sent = 1;
			maciisi_state = idle;
			if (req->reply_expected) {
				/* Note: only set this once we've
                                   successfully sent the packet */
				reading_reply = 1;
			} else {
				current_req = req->next;
				if (req->done)
					(*req->done)(req);
				/* Do any queued requests now */
				i = maciisi_start();
				if(i == 0 && need_sync) {
					/* Packet needs to be synced */
					maciisi_sync(current_req);
				}
				if(i != -EBUSY)
					need_sync = 0;
			}
		} else {
			/* Sending more stuff */
			/* Shift out */
			via[ACR] |= SR_OUT;
			/* Write */
			via[SR] = req->data[data_index++];
			/* Signal 'byte ready' */
			via[B] |= TACK;
		}
		break;

	case reading:
		/* Shift in */
		/* via[ACR] &= ~SR_OUT; */ /* Not in 2.2 */
		if (reply_len++ > 16) {
			printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
			via[B] |= TACK;
			udelay(ADB_DELAY);
			via[B] &= ~(TACK|TIP);
			maciisi_state = idle;
			i = maciisi_start();
			if(i == 0 && need_sync) {
				/* Packet needs to be synced */
				maciisi_sync(current_req);
			}
			if(i != -EBUSY)
				need_sync = 0;
			break;
		}
		/* Read data */
		*reply_ptr++ = via[SR];
		status = via[B] & (TIP|TREQ);
		/* ACK on/off */
		via[B] |= TACK;
		udelay(ADB_DELAY);
		via[B] &= ~TACK;	
		if (!(status & TREQ))
			break; /* more stuff to deal with */
		
		/* end of frame */
		via[B] &= ~TIP;
		tmp = via[SR]; /* That's what happens in 2.2 */
		udelay(ADB_DELAY); /* Give controller time to recover */

		/* end of packet, deal with it */
		if (reading_reply) {
			req = current_req;
			req->reply_len = reply_ptr - req->reply;
			if (req->data[0] == ADB_PACKET) {
				/* Have to adjust the reply from ADB commands */
				if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
					/* the 0x2 bit indicates no response */
					req->reply_len = 0;
				} else {
					/* leave just the command and result bytes in the reply */
					req->reply_len -= 2;
					memmove(req->reply, req->reply + 2, req->reply_len);
				}
			}
#ifdef DEBUG_MACIISI_ADB
			if (dump_reply) {
				int i;
				printk(KERN_DEBUG "maciisi_interrupt: reply is ");
				for (i = 0; i < req->reply_len; ++i)
					printk(" %.2x", req->reply[i]);
				printk("\n");
			}
#endif
			req->complete = 1;
			current_req = req->next;
			if (req->done)
				(*req->done)(req);
			/* Obviously, we got it */
			reading_reply = 0;
		} else {
			maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf);
		}
		maciisi_state = idle;
		status = via[B] & (TIP|TREQ);
		if (!(status & TREQ)) {
			/* Timeout?! More likely, another packet coming in already */
#ifdef DEBUG_MACIISI_ADB
			printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
			       status, via[IFR]);
#endif
#if 0
			udelay(ADB_DELAY);
			via[B] |= TIP;

			maciisi_state = reading;
			reading_reply = 0;
			reply_ptr = maciisi_rbuf;
#else
			/* Process the packet now */
			reading_reply = 0;
			goto switch_start;
#endif
			/* We used to do this... but the controller might actually have data for us */
			/* maciisi_stfu(); */
		}
		else {
			/* Do any queued requests now if possible */
			i = maciisi_start();
			if(i == 0 && need_sync) {
				/* Packet needs to be synced */
				maciisi_sync(current_req);
			}
			if(i != -EBUSY)
				need_sync = 0;
		}
		break;

	default:
		printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
	}
	local_irq_restore(flags);
	return IRQ_HANDLED;
}

static void
maciisi_input(unsigned char *buf, int nb)
{
#ifdef DEBUG_MACIISI_ADB
    int i;
#endif

    switch (buf[0]) {
    case ADB_PACKET:
	    adb_input(buf+2, nb-2, buf[1] & 0x40);
	    break;
    default:
#ifdef DEBUG_MACIISI_ADB
	    printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
	    for (i = 0; i < nb; ++i)
		    printk(" %.2x", buf[i]);
	    printk("\n");
#endif
	    break;
    }
}