Merge branch 'mini2440-dev-unlikely' into mini2440-dev
[linux-2.6/mini2440.git] / drivers / macintosh / via-cuda.c
blob62dd1fdafecf4c92954cf279be538d77aa5c4d27
1 /*
2 * Device driver for the via-cuda on Apple Powermacs.
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.
9 * Copyright (C) 1996 Paul Mackerras.
11 #include <stdarg.h>
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/adb.h>
17 #include <linux/cuda.h>
18 #include <linux/spinlock.h>
19 #include <linux/interrupt.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/mac_via.h>
27 #endif
28 #include <asm/io.h>
29 #include <asm/system.h>
30 #include <linux/init.h>
32 static volatile unsigned char __iomem *via;
33 static DEFINE_SPINLOCK(cuda_lock);
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 */
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) */
59 /* Bits in ACR */
60 #define SR_CTRL 0x1c /* Shift register control bits */
61 #define SR_EXT 0x0c /* Shift on external clock */
62 #define SR_OUT 0x10 /* Shift out if 1 */
64 /* Bits in IFR and IER */
65 #define IER_SET 0x80 /* set bits in IER */
66 #define IER_CLR 0 /* clear bits in IER */
67 #define SR_INT 0x04 /* Shift register full/empty */
69 static enum cuda_state {
70 idle,
71 sent_first_byte,
72 sending,
73 reading,
74 read_done,
75 awaiting_reply
76 } cuda_state;
78 static struct adb_request *current_req;
79 static struct adb_request *last_req;
80 static unsigned char cuda_rbuf[16];
81 static unsigned char *reply_ptr;
82 static int reading_reply;
83 static int data_index;
84 static int cuda_irq;
85 #ifdef CONFIG_PPC
86 static struct device_node *vias;
87 #endif
88 static int cuda_fully_inited;
90 #ifdef CONFIG_ADB
91 static int cuda_probe(void);
92 static int cuda_init(void);
93 static int cuda_send_request(struct adb_request *req, int sync);
94 static int cuda_adb_autopoll(int devs);
95 static int cuda_reset_adb_bus(void);
96 #endif /* CONFIG_ADB */
98 static int cuda_init_via(void);
99 static void cuda_start(void);
100 static irqreturn_t cuda_interrupt(int irq, void *arg);
101 static void cuda_input(unsigned char *buf, int nb);
102 void cuda_poll(void);
103 static int cuda_write(struct adb_request *req);
105 int cuda_request(struct adb_request *req,
106 void (*done)(struct adb_request *), int nbytes, ...);
108 #ifdef CONFIG_ADB
109 struct adb_driver via_cuda_driver = {
110 "CUDA",
111 cuda_probe,
112 cuda_init,
113 cuda_send_request,
114 cuda_adb_autopoll,
115 cuda_poll,
116 cuda_reset_adb_bus
118 #endif /* CONFIG_ADB */
120 #ifdef CONFIG_PPC
121 int __init find_via_cuda(void)
123 struct adb_request req;
124 phys_addr_t taddr;
125 const u32 *reg;
126 int err;
128 if (vias != 0)
129 return 1;
130 vias = of_find_node_by_name(NULL, "via-cuda");
131 if (vias == 0)
132 return 0;
134 reg = of_get_property(vias, "reg", NULL);
135 if (reg == NULL) {
136 printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
137 goto fail;
139 taddr = of_translate_address(vias, reg);
140 if (taddr == 0) {
141 printk(KERN_ERR "via-cuda: Can't translate address !\n");
142 goto fail;
144 via = ioremap(taddr, 0x2000);
145 if (via == NULL) {
146 printk(KERN_ERR "via-cuda: Can't map address !\n");
147 goto fail;
150 cuda_state = idle;
151 sys_ctrler = SYS_CTRLER_CUDA;
153 err = cuda_init_via();
154 if (err) {
155 printk(KERN_ERR "cuda_init_via() failed\n");
156 via = NULL;
157 return 0;
160 /* Clear and enable interrupts, but only on PPC. On 68K it's done */
161 /* for us by the main VIA driver in arch/m68k/mac/via.c */
163 out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */
164 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
166 /* enable autopoll */
167 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
168 while (!req.complete)
169 cuda_poll();
171 return 1;
173 fail:
174 of_node_put(vias);
175 vias = NULL;
176 return 0;
178 #endif /* CONFIG_PPC */
180 static int __init via_cuda_start(void)
182 if (via == NULL)
183 return -ENODEV;
185 #ifdef CONFIG_MAC
186 cuda_irq = IRQ_MAC_ADB;
187 #else /* CONFIG_MAC */
188 cuda_irq = irq_of_parse_and_map(vias, 0);
189 if (cuda_irq == NO_IRQ) {
190 printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
191 vias->full_name);
192 return -ENODEV;
194 #endif /* CONFIG_MAC */
196 if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
197 printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
198 return -EAGAIN;
201 printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
203 cuda_fully_inited = 1;
204 return 0;
207 device_initcall(via_cuda_start);
209 #ifdef CONFIG_ADB
210 static int
211 cuda_probe(void)
213 #ifdef CONFIG_PPC
214 if (sys_ctrler != SYS_CTRLER_CUDA)
215 return -ENODEV;
216 #else
217 if (macintosh_config->adb_type != MAC_ADB_CUDA)
218 return -ENODEV;
219 via = via1;
220 #endif
221 return 0;
224 static int __init
225 cuda_init(void)
227 #ifdef CONFIG_PPC
228 if (via == NULL)
229 return -ENODEV;
230 return 0;
231 #else
232 int err = cuda_init_via();
233 if (err) {
234 printk(KERN_ERR "cuda_init_via() failed\n");
235 return -ENODEV;
237 out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
239 return via_cuda_start();
240 #endif
242 #endif /* CONFIG_ADB */
244 #define WAIT_FOR(cond, what) \
245 do { \
246 int x; \
247 for (x = 1000; !(cond); --x) { \
248 if (x == 0) { \
249 printk("Timeout waiting for " what "\n"); \
250 return -ENXIO; \
252 udelay(100); \
254 } while (0)
256 static int
257 cuda_init_via(void)
259 out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
260 out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */
261 out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
262 (void)in_8(&via[SR]); /* clear any left-over data */
263 #ifdef CONFIG_PPC
264 out_8(&via[IER], 0x7f); /* disable interrupts from VIA */
265 (void)in_8(&via[IER]);
266 #else
267 out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */
268 #endif
270 /* delay 4ms and then clear any pending interrupt */
271 mdelay(4);
272 (void)in_8(&via[SR]);
273 out_8(&via[IFR], SR_INT);
275 /* sync with the CUDA - assert TACK without TIP */
276 out_8(&via[B], in_8(&via[B]) & ~TACK);
278 /* wait for the CUDA to assert TREQ in response */
279 WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
281 /* wait for the interrupt and then clear it */
282 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
283 (void)in_8(&via[SR]);
284 out_8(&via[IFR], SR_INT);
286 /* finish the sync by negating TACK */
287 out_8(&via[B], in_8(&via[B]) | TACK);
289 /* wait for the CUDA to negate TREQ and the corresponding interrupt */
290 WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
291 WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
292 (void)in_8(&via[SR]);
293 out_8(&via[IFR], SR_INT);
294 out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */
296 return 0;
299 #ifdef CONFIG_ADB
300 /* Send an ADB command */
301 static int
302 cuda_send_request(struct adb_request *req, int sync)
304 int i;
306 if ((via == NULL) || !cuda_fully_inited) {
307 req->complete = 1;
308 return -ENXIO;
311 req->reply_expected = 1;
313 i = cuda_write(req);
314 if (i)
315 return i;
317 if (sync) {
318 while (!req->complete)
319 cuda_poll();
321 return 0;
325 /* Enable/disable autopolling */
326 static int
327 cuda_adb_autopoll(int devs)
329 struct adb_request req;
331 if ((via == NULL) || !cuda_fully_inited)
332 return -ENXIO;
334 cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
335 while (!req.complete)
336 cuda_poll();
337 return 0;
340 /* Reset adb bus - how do we do this?? */
341 static int
342 cuda_reset_adb_bus(void)
344 struct adb_request req;
346 if ((via == NULL) || !cuda_fully_inited)
347 return -ENXIO;
349 cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */
350 while (!req.complete)
351 cuda_poll();
352 return 0;
354 #endif /* CONFIG_ADB */
355 /* Construct and send a cuda request */
357 cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
358 int nbytes, ...)
360 va_list list;
361 int i;
363 if (via == NULL) {
364 req->complete = 1;
365 return -ENXIO;
368 req->nbytes = nbytes;
369 req->done = done;
370 va_start(list, nbytes);
371 for (i = 0; i < nbytes; ++i)
372 req->data[i] = va_arg(list, int);
373 va_end(list);
374 req->reply_expected = 1;
375 return cuda_write(req);
378 static int
379 cuda_write(struct adb_request *req)
381 unsigned long flags;
383 if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
384 req->complete = 1;
385 return -EINVAL;
387 req->next = NULL;
388 req->sent = 0;
389 req->complete = 0;
390 req->reply_len = 0;
392 spin_lock_irqsave(&cuda_lock, flags);
393 if (current_req != 0) {
394 last_req->next = req;
395 last_req = req;
396 } else {
397 current_req = req;
398 last_req = req;
399 if (cuda_state == idle)
400 cuda_start();
402 spin_unlock_irqrestore(&cuda_lock, flags);
404 return 0;
407 static void
408 cuda_start(void)
410 struct adb_request *req;
412 /* assert cuda_state == idle */
413 /* get the packet to send */
414 req = current_req;
415 if (req == 0)
416 return;
417 if ((in_8(&via[B]) & TREQ) == 0)
418 return; /* a byte is coming in from the CUDA */
420 /* set the shift register to shift out and send a byte */
421 out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
422 out_8(&via[SR], req->data[0]);
423 out_8(&via[B], in_8(&via[B]) & ~TIP);
424 cuda_state = sent_first_byte;
427 void
428 cuda_poll(void)
430 /* cuda_interrupt only takes a normal lock, we disable
431 * interrupts here to avoid re-entering and thus deadlocking.
433 disable_irq(cuda_irq);
434 cuda_interrupt(0, NULL);
435 enable_irq(cuda_irq);
438 static irqreturn_t
439 cuda_interrupt(int irq, void *arg)
441 int status;
442 struct adb_request *req = NULL;
443 unsigned char ibuf[16];
444 int ibuf_len = 0;
445 int complete = 0;
447 spin_lock(&cuda_lock);
449 /* On powermacs, this handler is registered for the VIA IRQ. But it uses
450 * just the shift register IRQ -- other VIA interrupt sources are disabled.
451 * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
452 * we are polling, the shift register IRQ flag has already been cleared.
455 #ifdef CONFIG_MAC
456 if (!arg)
457 #endif
459 if ((in_8(&via[IFR]) & SR_INT) == 0) {
460 spin_unlock(&cuda_lock);
461 return IRQ_NONE;
462 } else {
463 out_8(&via[IFR], SR_INT);
467 status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
468 /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
469 switch (cuda_state) {
470 case idle:
471 /* CUDA has sent us the first byte of data - unsolicited */
472 if (status != TREQ)
473 printk("cuda: state=idle, status=%x\n", status);
474 (void)in_8(&via[SR]);
475 out_8(&via[B], in_8(&via[B]) & ~TIP);
476 cuda_state = reading;
477 reply_ptr = cuda_rbuf;
478 reading_reply = 0;
479 break;
481 case awaiting_reply:
482 /* CUDA has sent us the first byte of data of a reply */
483 if (status != TREQ)
484 printk("cuda: state=awaiting_reply, status=%x\n", status);
485 (void)in_8(&via[SR]);
486 out_8(&via[B], in_8(&via[B]) & ~TIP);
487 cuda_state = reading;
488 reply_ptr = current_req->reply;
489 reading_reply = 1;
490 break;
492 case sent_first_byte:
493 if (status == TREQ + TIP + SR_OUT) {
494 /* collision */
495 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
496 (void)in_8(&via[SR]);
497 out_8(&via[B], in_8(&via[B]) | TIP | TACK);
498 cuda_state = idle;
499 } else {
500 /* assert status == TIP + SR_OUT */
501 if (status != TIP + SR_OUT)
502 printk("cuda: state=sent_first_byte status=%x\n", status);
503 out_8(&via[SR], current_req->data[1]);
504 out_8(&via[B], in_8(&via[B]) ^ TACK);
505 data_index = 2;
506 cuda_state = sending;
508 break;
510 case sending:
511 req = current_req;
512 if (data_index >= req->nbytes) {
513 out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
514 (void)in_8(&via[SR]);
515 out_8(&via[B], in_8(&via[B]) | TACK | TIP);
516 req->sent = 1;
517 if (req->reply_expected) {
518 cuda_state = awaiting_reply;
519 } else {
520 current_req = req->next;
521 complete = 1;
522 /* not sure about this */
523 cuda_state = idle;
524 cuda_start();
526 } else {
527 out_8(&via[SR], req->data[data_index++]);
528 out_8(&via[B], in_8(&via[B]) ^ TACK);
530 break;
532 case reading:
533 *reply_ptr++ = in_8(&via[SR]);
534 if (status == TIP) {
535 /* that's all folks */
536 out_8(&via[B], in_8(&via[B]) | TACK | TIP);
537 cuda_state = read_done;
538 } else {
539 /* assert status == TIP | TREQ */
540 if (status != TIP + TREQ)
541 printk("cuda: state=reading status=%x\n", status);
542 out_8(&via[B], in_8(&via[B]) ^ TACK);
544 break;
546 case read_done:
547 (void)in_8(&via[SR]);
548 if (reading_reply) {
549 req = current_req;
550 req->reply_len = reply_ptr - req->reply;
551 if (req->data[0] == ADB_PACKET) {
552 /* Have to adjust the reply from ADB commands */
553 if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
554 /* the 0x2 bit indicates no response */
555 req->reply_len = 0;
556 } else {
557 /* leave just the command and result bytes in the reply */
558 req->reply_len -= 2;
559 memmove(req->reply, req->reply + 2, req->reply_len);
562 current_req = req->next;
563 complete = 1;
564 } else {
565 /* This is tricky. We must break the spinlock to call
566 * cuda_input. However, doing so means we might get
567 * re-entered from another CPU getting an interrupt
568 * or calling cuda_poll(). I ended up using the stack
569 * (it's only for 16 bytes) and moving the actual
570 * call to cuda_input to outside of the lock.
572 ibuf_len = reply_ptr - cuda_rbuf;
573 memcpy(ibuf, cuda_rbuf, ibuf_len);
575 if (status == TREQ) {
576 out_8(&via[B], in_8(&via[B]) & ~TIP);
577 cuda_state = reading;
578 reply_ptr = cuda_rbuf;
579 reading_reply = 0;
580 } else {
581 cuda_state = idle;
582 cuda_start();
584 break;
586 default:
587 printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
589 spin_unlock(&cuda_lock);
590 if (complete && req) {
591 void (*done)(struct adb_request *) = req->done;
592 mb();
593 req->complete = 1;
594 /* Here, we assume that if the request has a done member, the
595 * struct request will survive to setting req->complete to 1
597 if (done)
598 (*done)(req);
600 if (ibuf_len)
601 cuda_input(ibuf, ibuf_len);
602 return IRQ_HANDLED;
605 static void
606 cuda_input(unsigned char *buf, int nb)
608 int i;
610 switch (buf[0]) {
611 case ADB_PACKET:
612 #ifdef CONFIG_XMON
613 if (nb == 5 && buf[2] == 0x2c) {
614 extern int xmon_wants_key, xmon_adb_keycode;
615 if (xmon_wants_key) {
616 xmon_adb_keycode = buf[3];
617 return;
620 #endif /* CONFIG_XMON */
621 #ifdef CONFIG_ADB
622 adb_input(buf+2, nb-2, buf[1] & 0x40);
623 #endif /* CONFIG_ADB */
624 break;
626 default:
627 printk("data from cuda (%d bytes):", nb);
628 for (i = 0; i < nb; ++i)
629 printk(" %.2x", buf[i]);
630 printk("\n");