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