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