1 /*
2 * Device driver for the IIsi-style ADB on some Mac LC and II-class machines
3 *
4 * Based on via-cuda.c and via-macii.c, as well as the original
5 * adb-bus.c, which in turn is somewhat influenced by (but uses no
6 * code from) the NetBSD HWDIRECT ADB code. Original IIsi driver work
7 * was done by Robert Thompson and integrated into the old style
8 * driver by Michael Schmitz.
9 *
10 * Original sources (c) Alan Cox, Paul Mackerras, and others.
11 *
12 * Rewritten for Unified ADB by David Huggins-Daines <dhd@debian.org>
13 *
14 * 7/13/2000- extensive changes by Andrew McPherson <andrew@macduff.dhs.org>
15 * Works about 30% of the time now.
16 */
17
18 #include <linux/types.h>
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/adb.h>
23 #include <linux/cuda.h>
24 #include <linux/delay.h>
25 #include <asm/macintosh.h>
26 #include <asm/macints.h>
27 #include <asm/machw.h>
28 #include <asm/mac_via.h>
29
30 static volatile unsigned char *via;
31
32 /* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
33 #define RS 0x200 /* skip between registers */
34 #define B 0 /* B-side data */
35 #define A RS /* A-side data */
36 #define DIRB (2*RS) /* B-side direction (1=output) */
37 #define DIRA (3*RS) /* A-side direction (1=output) */
38 #define SR (10*RS) /* Shift register */
39 #define ACR (11*RS) /* Auxiliary control register */
40 #define IFR (13*RS) /* Interrupt flag register */
41 #define IER (14*RS) /* Interrupt enable register */
42
43 /* Bits in B data register: all active low */
44 #define TREQ 0x08 /* Transfer request (input) */
45 #define TACK 0x10 /* Transfer acknowledge (output) */
46 #define TIP 0x20 /* Transfer in progress (output) */
47 #define ST_MASK 0x30 /* mask for selecting ADB state bits */
48
49 /* Bits in ACR */
50 #define SR_CTRL 0x1c /* Shift register control bits */
51 #define SR_EXT 0x0c /* Shift on external clock */
52 #define SR_OUT 0x10 /* Shift out if 1 */
53
54 /* Bits in IFR and IER */
55 #define IER_SET 0x80 /* set bits in IER */
56 #define IER_CLR 0 /* clear bits in IER */
57 #define SR_INT 0x04 /* Shift register full/empty */
58 #define SR_DATA 0x08 /* Shift register data */
59 #define SR_CLOCK 0x10 /* Shift register clock */
60
61 #define ADB_DELAY 150
62
63 #undef DEBUG_MACIISI_ADB
64
65 static struct adb_request* current_req = NULL;
66 static struct adb_request* last_req = NULL;
67 static unsigned char maciisi_rbuf[16];
68 static unsigned char *reply_ptr = NULL;
69 static int data_index;
70 static int reading_reply;
71 static int reply_len;
72 static int tmp;
73 static int need_sync;
74
75 static enum maciisi_state {
76 idle,
77 sending,
78 reading,
79 } maciisi_state;
80
81 static int maciisi_probe(void);
82 static int maciisi_init(void);
83 static int maciisi_send_request(struct adb_request* req, int sync);
84 static void maciisi_sync(struct adb_request *req);
85 static int maciisi_write(struct adb_request* req);
86 static void maciisi_interrupt(int irq, void* arg, struct pt_regs* regs);
87 static void maciisi_input(unsigned char *buf, int nb, struct pt_regs *regs);
88 static int maciisi_init_via(void);
89 static void maciisi_poll(void);
90 static int maciisi_start(void);
91
92 struct adb_driver via_maciisi_driver = {
93 "Mac IIsi",
94 maciisi_probe,
95 maciisi_init,
96 maciisi_send_request,
97 NULL, /* maciisi_adb_autopoll, */
98 maciisi_poll,
99 NULL /* maciisi_reset_adb_bus */
100 };
101
102 static int
maciisi_probe(void)103 maciisi_probe(void)
104 {
105 if (macintosh_config->adb_type != MAC_ADB_IISI)
106 return -ENODEV;
107
108 via = via1;
109 return 0;
110 }
111
112 static int
maciisi_init(void)113 maciisi_init(void)
114 {
115 int err;
116
117 if (via == NULL)
118 return -ENODEV;
119
120 if ((err = maciisi_init_via())) {
121 printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
122 via = NULL;
123 return err;
124 }
125
126 if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK | IRQ_FLG_FAST,
127 "ADB", maciisi_interrupt)) {
128 printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
129 return -EAGAIN;
130 }
131
132 printk("adb: Mac IIsi driver v0.2 for Unified ADB.\n");
133 return 0;
134 }
135
136 /* Flush data from the ADB controller */
137 static void
maciisi_stfu(void)138 maciisi_stfu(void)
139 {
140 int status = via[B] & (TIP|TREQ);
141
142 if (status & TREQ) {
143 #ifdef DEBUG_MACIISI_ADB
144 printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
145 #endif
146 return;
147 }
148
149 udelay(ADB_DELAY);
150 via[ACR] &= ~SR_OUT;
151 via[IER] = IER_CLR | SR_INT;
152
153 udelay(ADB_DELAY);
154
155 status = via[B] & (TIP|TREQ);
156
157 if (!(status & TREQ))
158 {
159 via[B] |= TIP;
160
161 while(1)
162 {
163 int poll_timeout = ADB_DELAY * 5;
164 /* Poll for SR interrupt */
165 while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
166 status = via[B] & (TIP|TREQ);
167
168 tmp = via[SR]; /* Clear shift register */
169 #ifdef DEBUG_MACIISI_ADB
170 printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d data %x\n",
171 status, poll_timeout, tmp);
172 #endif
173 if(via[B] & TREQ)
174 break;
175
176 /* ACK on-off */
177 via[B] |= TACK;
178 udelay(ADB_DELAY);
179 via[B] &= ~TACK;
180 }
181
182 /* end frame */
183 via[B] &= ~TIP;
184 udelay(ADB_DELAY);
185 }
186
187 via[IER] = IER_SET | SR_INT;
188 }
189
190 /* All specifically VIA-related initialization goes here */
191 static int
maciisi_init_via(void)192 maciisi_init_via(void)
193 {
194 int i;
195
196 /* Set the lines up. We want TREQ as input TACK|TIP as output */
197 via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
198 /* Shift register on input */
199 via[ACR] = (via[ACR] & ~SR_CTRL) | SR_EXT;
200 #ifdef DEBUG_MACIISI_ADB
201 printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
202 #endif
203 /* Wipe any pending data and int */
204 tmp = via[SR];
205 /* Enable keyboard interrupts */
206 via[IER] = IER_SET | SR_INT;
207 /* Set initial state: idle */
208 via[B] &= ~(TACK|TIP);
209 /* Clear interrupt bit */
210 via[IFR] = SR_INT;
211
212 for(i = 0; i < 60; i++) {
213 udelay(ADB_DELAY);
214 maciisi_stfu();
215 udelay(ADB_DELAY);
216 if(via[B] & TREQ)
217 break;
218 }
219 if (i == 60)
220 printk(KERN_ERR "maciisi_init_via: bus jam?\n");
221
222 maciisi_state = idle;
223 need_sync = 0;
224
225 return 0;
226 }
227
228 /* Send a request, possibly waiting for a reply */
229 static int
maciisi_send_request(struct adb_request * req,int sync)230 maciisi_send_request(struct adb_request* req, int sync)
231 {
232 int i;
233
234 #ifdef DEBUG_MACIISI_ADB
235 static int dump_packet = 0;
236 #endif
237
238 if (via == NULL) {
239 req->complete = 1;
240 return -ENXIO;
241 }
242
243 #ifdef DEBUG_MACIISI_ADB
244 if (dump_packet) {
245 printk(KERN_DEBUG "maciisi_send_request:");
246 for (i = 0; i < req->nbytes; i++) {
247 printk(" %.2x", req->data[i]);
248 }
249 printk(" sync %d\n", sync);
250 }
251 #endif
252
253 req->reply_expected = 1;
254
255 i = maciisi_write(req);
256 if (i)
257 {
258 /* Normally, if a packet requires syncing, that happens at the end of
259 * maciisi_send_request. But if the transfer fails, it will be restarted
260 * by maciisi_interrupt(). We use need_sync to tell maciisi_interrupt
261 * when to sync a packet that it sends out.
262 *
263 * Suggestions on a better way to do this are welcome.
264 */
265 if(i == -EBUSY && sync)
266 need_sync = 1;
267 else
268 need_sync = 0;
269 return i;
270 }
271 if(sync)
272 maciisi_sync(req);
273
274 return 0;
275 }
276
277 /* Poll the ADB chip until the request completes */
maciisi_sync(struct adb_request * req)278 static void maciisi_sync(struct adb_request *req)
279 {
280 int count = 0;
281
282 #ifdef DEBUG_MACIISI_ADB
283 printk(KERN_DEBUG "maciisi_sync called\n");
284 #endif
285
286 /* If for some reason the ADB chip shuts up on us, we want to avoid an endless loop. */
287 while (!req->complete && count++ < 50) {
288 maciisi_poll();
289 }
290 /* This could be BAD... when the ADB controller doesn't respond
291 * for this long, it's probably not coming back :-( */
292 if(count >= 50) /* Hopefully shouldn't happen */
293 printk(KERN_ERR "maciisi_send_request: poll timed out!\n");
294 }
295
296 /* Enqueue a request, and run the queue if possible */
297 static int
maciisi_write(struct adb_request * req)298 maciisi_write(struct adb_request* req)
299 {
300 unsigned long flags;
301 int i;
302
303 /* We will accept CUDA packets - the VIA sends them to us, so
304 it figures that we should be able to send them to it */
305 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
306 printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
307 req->complete = 1;
308 return -EINVAL;
309 }
310 req->next = 0;
311 req->sent = 0;
312 req->complete = 0;
313 req->reply_len = 0;
314
315 save_flags(flags);
316 cli();
317
318 if (current_req) {
319 last_req->next = req;
320 last_req = req;
321 } else {
322 current_req = req;
323 last_req = req;
324 }
325 if (maciisi_state == idle)
326 {
327 i = maciisi_start();
328 if(i != 0)
329 {
330 restore_flags(flags);
331 return i;
332 }
333 }
334 else
335 {
336 #ifdef DEBUG_MACIISI_ADB
337 printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
338 #endif
339 restore_flags(flags);
340 return -EBUSY;
341 }
342
343 restore_flags(flags);
344
345 return 0;
346 }
347
348 static int
maciisi_start(void)349 maciisi_start(void)
350 {
351 struct adb_request* req;
352 int status;
353
354 #ifdef DEBUG_MACIISI_ADB
355 status = via[B] & (TIP | TREQ);
356
357 printk(KERN_DEBUG "maciisi_start called, state=%d, status=%x, ifr=%x\n", maciisi_state, status, via[IFR]);
358 #endif
359
360 if (maciisi_state != idle) {
361 /* shouldn't happen */
362 printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
363 return -EBUSY;
364 }
365
366 req = current_req;
367 if (req == NULL)
368 return -EINVAL;
369
370 status = via[B] & (TIP|TREQ);
371 if (!(status & TREQ)) {
372 #ifdef DEBUG_MACIISI_ADB
373 printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
374 #endif
375 return -EBUSY;
376 }
377
378 /* Okay, send */
379 #ifdef DEBUG_MACIISI_ADB
380 printk(KERN_DEBUG "maciisi_start: sending\n");
381 #endif
382 /* Set state to active */
383 via[B] |= TIP;
384 /* ACK off */
385 via[B] &= ~TACK;
386 /* Delay */
387 udelay(ADB_DELAY);
388 /* Shift out and send */
389 via[ACR] |= SR_OUT;
390 via[SR] = req->data[0];
391 data_index = 1;
392 /* ACK on */
393 via[B] |= TACK;
394 maciisi_state = sending;
395
396 return 0;
397 }
398
399 void
maciisi_poll(void)400 maciisi_poll(void)
401 {
402 unsigned long flags;
403
404 save_flags(flags);
405 cli();
406 if (via[IFR] & SR_INT) {
407 maciisi_interrupt(0, 0, 0);
408 }
409 else /* avoid calling this function too quickly in a loop */
410 udelay(ADB_DELAY);
411
412 restore_flags(flags);
413 }
414
415 /* Shift register interrupt - this is *supposed* to mean that the
416 register is either full or empty. In practice, I have no idea what
417 it means :( */
418 static void
maciisi_interrupt(int irq,void * arg,struct pt_regs * regs)419 maciisi_interrupt(int irq, void* arg, struct pt_regs* regs)
420 {
421 int status;
422 struct adb_request *req;
423 #ifdef DEBUG_MACIISI_ADB
424 static int dump_reply = 0;
425 #endif
426 int i;
427 unsigned long flags;
428
429 save_flags(flags);
430 cli();
431
432 status = via[B] & (TIP|TREQ);
433 #ifdef DEBUG_MACIISI_ADB
434 printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
435 #endif
436
437 if (!(via[IFR] & SR_INT)) {
438 /* Shouldn't happen, we hope */
439 printk(KERN_ERR "maciisi_interrupt: called without interrupt flag set\n");
440 restore_flags(flags);
441 return;
442 }
443
444 /* Clear the interrupt */
445 /* via[IFR] = SR_INT; */
446
447 switch_start:
448 switch (maciisi_state) {
449 case idle:
450 if (status & TIP)
451 printk(KERN_ERR "maciisi_interrupt: state is idle but TIP asserted!\n");
452
453 if(!reading_reply)
454 udelay(ADB_DELAY);
455 /* Shift in */
456 via[ACR] &= ~SR_OUT;
457 /* Signal start of frame */
458 via[B] |= TIP;
459 /* Clear the interrupt (throw this value on the floor, it's useless) */
460 tmp = via[SR];
461 /* ACK adb chip, high-low */
462 via[B] |= TACK;
463 udelay(ADB_DELAY);
464 via[B] &= ~TACK;
465 reply_len = 0;
466 maciisi_state = reading;
467 if (reading_reply) {
468 reply_ptr = current_req->reply;
469 } else {
470 reply_ptr = maciisi_rbuf;
471 }
472 break;
473
474 case sending:
475 /* via[SR]; */
476 /* Set ACK off */
477 via[B] &= ~TACK;
478 req = current_req;
479
480 if (!(status & TREQ)) {
481 /* collision */
482 printk(KERN_ERR "maciisi_interrupt: send collision\n");
483 /* Set idle and input */
484 via[ACR] &= ~SR_OUT;
485 tmp = via[SR];
486 via[B] &= ~TIP;
487 /* Must re-send */
488 reading_reply = 0;
489 reply_len = 0;
490 maciisi_state = idle;
491 udelay(ADB_DELAY);
492 /* process this now, because the IFR has been cleared */
493 goto switch_start;
494 }
495
496 udelay(ADB_DELAY);
497
498 if (data_index >= req->nbytes) {
499 /* Sent the whole packet, put the bus back in idle state */
500 /* Shift in, we are about to read a reply (hopefully) */
501 via[ACR] &= ~SR_OUT;
502 tmp = via[SR];
503 /* End of frame */
504 via[B] &= ~TIP;
505 req->sent = 1;
506 maciisi_state = idle;
507 if (req->reply_expected) {
508 /* Note: only set this once we've
509 successfully sent the packet */
510 reading_reply = 1;
511 } else {
512 current_req = req->next;
513 if (req->done)
514 (*req->done)(req);
515 /* Do any queued requests now */
516 i = maciisi_start();
517 if(i == 0 && need_sync) {
518 /* Packet needs to be synced */
519 maciisi_sync(current_req);
520 }
521 if(i != -EBUSY)
522 need_sync = 0;
523 }
524 } else {
525 /* Sending more stuff */
526 /* Shift out */
527 via[ACR] |= SR_OUT;
528 /* Write */
529 via[SR] = req->data[data_index++];
530 /* Signal 'byte ready' */
531 via[B] |= TACK;
532 }
533 break;
534
535 case reading:
536 /* Shift in */
537 /* via[ACR] &= ~SR_OUT; */ /* Not in 2.2 */
538 if (reply_len++ > 16) {
539 printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
540 via[B] |= TACK;
541 udelay(ADB_DELAY);
542 via[B] &= ~(TACK|TIP);
543 maciisi_state = idle;
544 i = maciisi_start();
545 if(i == 0 && need_sync) {
546 /* Packet needs to be synced */
547 maciisi_sync(current_req);
548 }
549 if(i != -EBUSY)
550 need_sync = 0;
551 break;
552 }
553 /* Read data */
554 *reply_ptr++ = via[SR];
555 status = via[B] & (TIP|TREQ);
556 /* ACK on/off */
557 via[B] |= TACK;
558 udelay(ADB_DELAY);
559 via[B] &= ~TACK;
560 if (!(status & TREQ))
561 break; /* more stuff to deal with */
562
563 /* end of frame */
564 via[B] &= ~TIP;
565 tmp = via[SR]; /* That's what happens in 2.2 */
566 udelay(ADB_DELAY); /* Give controller time to recover */
567
568 /* end of packet, deal with it */
569 if (reading_reply) {
570 req = current_req;
571 req->reply_len = reply_ptr - req->reply;
572 if (req->data[0] == ADB_PACKET) {
573 /* Have to adjust the reply from ADB commands */
574 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
575 /* the 0x2 bit indicates no response */
576 req->reply_len = 0;
577 } else {
578 /* leave just the command and result bytes in the reply */
579 req->reply_len -= 2;
580 memmove(req->reply, req->reply + 2, req->reply_len);
581 }
582 }
583 #ifdef DEBUG_MACIISI_ADB
584 if (dump_reply) {
585 int i;
586 printk(KERN_DEBUG "maciisi_interrupt: reply is ");
587 for (i = 0; i < req->reply_len; ++i)
588 printk(" %.2x", req->reply[i]);
589 printk("\n");
590 }
591 #endif
592 req->complete = 1;
593 current_req = req->next;
594 if (req->done)
595 (*req->done)(req);
596 /* Obviously, we got it */
597 reading_reply = 0;
598 } else {
599 maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf, regs);
600 }
601 maciisi_state = idle;
602 status = via[B] & (TIP|TREQ);
603 if (!(status & TREQ)) {
604 /* Timeout?! More likely, another packet coming in already */
605 #ifdef DEBUG_MACIISI_ADB
606 printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
607 status, via[IFR]);
608 #endif
609 #if 0
610 udelay(ADB_DELAY);
611 via[B] |= TIP;
612
613 maciisi_state = reading;
614 reading_reply = 0;
615 reply_ptr = maciisi_rbuf;
616 #else
617 /* Process the packet now */
618 reading_reply = 0;
619 goto switch_start;
620 #endif
621 /* We used to do this... but the controller might actually have data for us */
622 /* maciisi_stfu(); */
623 }
624 else {
625 /* Do any queued requests now if possible */
626 i = maciisi_start();
627 if(i == 0 && need_sync) {
628 /* Packet needs to be synced */
629 maciisi_sync(current_req);
630 }
631 if(i != -EBUSY)
632 need_sync = 0;
633 }
634 break;
635
636 default:
637 printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
638 }
639 restore_flags(flags);
640 }
641
642 static void
maciisi_input(unsigned char * buf,int nb,struct pt_regs * regs)643 maciisi_input(unsigned char *buf, int nb, struct pt_regs *regs)
644 {
645 #ifdef DEBUG_MACIISI_ADB
646 int i;
647 #endif
648
649 switch (buf[0]) {
650 case ADB_PACKET:
651 adb_input(buf+2, nb-2, regs, buf[1] & 0x40);
652 break;
653 default:
654 #ifdef DEBUG_MACIISI_ADB
655 printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
656 for (i = 0; i < nb; ++i)
657 printk(" %.2x", buf[i]);
658 printk("\n");
659 #endif
660 break;
661 }
662 }
663