xref: /openbmc/linux/drivers/macintosh/via-cuda.c (revision ac3cb6de)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Device driver for the Cuda and Egret system controllers found on PowerMacs
4  * and 68k Macs.
5  *
6  * The Cuda or Egret is a 6805 microcontroller interfaced to the 6522 VIA.
7  * This MCU controls system power, Parameter RAM, Real Time Clock and the
8  * Apple Desktop Bus (ADB) that connects to the keyboard and mouse.
9  *
10  * Copyright (C) 1996 Paul Mackerras.
11  */
12 #include <linux/stdarg.h>
13 #include <linux/types.h>
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/delay.h>
17 #include <linux/adb.h>
18 #include <linux/cuda.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 
24 #ifdef CONFIG_PPC
25 #include <asm/machdep.h>
26 #include <asm/pmac_feature.h>
27 #else
28 #include <asm/macintosh.h>
29 #include <asm/macints.h>
30 #include <asm/mac_via.h>
31 #endif
32 #include <asm/io.h>
33 #include <linux/init.h>
34 
35 static volatile unsigned char __iomem *via;
36 static DEFINE_SPINLOCK(cuda_lock);
37 
38 /* VIA registers - spaced 0x200 bytes apart */
39 #define RS		0x200		/* skip between registers */
40 #define B		0		/* B-side data */
41 #define A		RS		/* A-side data */
42 #define DIRB		(2*RS)		/* B-side direction (1=output) */
43 #define DIRA		(3*RS)		/* A-side direction (1=output) */
44 #define T1CL		(4*RS)		/* Timer 1 ctr/latch (low 8 bits) */
45 #define T1CH		(5*RS)		/* Timer 1 counter (high 8 bits) */
46 #define T1LL		(6*RS)		/* Timer 1 latch (low 8 bits) */
47 #define T1LH		(7*RS)		/* Timer 1 latch (high 8 bits) */
48 #define T2CL		(8*RS)		/* Timer 2 ctr/latch (low 8 bits) */
49 #define T2CH		(9*RS)		/* Timer 2 counter (high 8 bits) */
50 #define SR		(10*RS)		/* Shift register */
51 #define ACR		(11*RS)		/* Auxiliary control register */
52 #define PCR		(12*RS)		/* Peripheral control register */
53 #define IFR		(13*RS)		/* Interrupt flag register */
54 #define IER		(14*RS)		/* Interrupt enable register */
55 #define ANH		(15*RS)		/* A-side data, no handshake */
56 
57 /*
58  * When the Cuda design replaced the Egret, some signal names and
59  * logic sense changed. They all serve the same purposes, however.
60  *
61  *   VIA pin       |  Egret pin
62  * ----------------+------------------------------------------
63  *   PB3 (input)   |  Transceiver session   (active low)
64  *   PB4 (output)  |  VIA full              (active high)
65  *   PB5 (output)  |  System session        (active high)
66  *
67  *   VIA pin       |  Cuda pin
68  * ----------------+------------------------------------------
69  *   PB3 (input)   |  Transfer request      (active low)
70  *   PB4 (output)  |  Byte acknowledge      (active low)
71  *   PB5 (output)  |  Transfer in progress  (active low)
72  */
73 
74 /* Bits in Port B data register */
75 #define TREQ		0x08		/* Transfer request */
76 #define TACK		0x10		/* Transfer acknowledge */
77 #define TIP		0x20		/* Transfer in progress */
78 
79 /* Bits in ACR */
80 #define SR_CTRL		0x1c		/* Shift register control bits */
81 #define SR_EXT		0x0c		/* Shift on external clock */
82 #define SR_OUT		0x10		/* Shift out if 1 */
83 
84 /* Bits in IFR and IER */
85 #define IER_SET		0x80		/* set bits in IER */
86 #define IER_CLR		0		/* clear bits in IER */
87 #define SR_INT		0x04		/* Shift register full/empty */
88 
89 /* Duration of byte acknowledgement pulse (us) */
90 #define EGRET_TACK_ASSERTED_DELAY	300
91 #define EGRET_TACK_NEGATED_DELAY	400
92 
93 /* Interval from interrupt to start of session (us) */
94 #define EGRET_SESSION_DELAY		450
95 
96 #ifdef CONFIG_PPC
97 #define mcu_is_egret	false
98 #else
99 static bool mcu_is_egret;
100 #endif
101 
102 static inline bool TREQ_asserted(u8 portb)
103 {
104 	return !(portb & TREQ);
105 }
106 
107 static inline void assert_TIP(void)
108 {
109 	if (mcu_is_egret) {
110 		udelay(EGRET_SESSION_DELAY);
111 		out_8(&via[B], in_8(&via[B]) | TIP);
112 	} else
113 		out_8(&via[B], in_8(&via[B]) & ~TIP);
114 }
115 
116 static inline void assert_TIP_and_TACK(void)
117 {
118 	if (mcu_is_egret) {
119 		udelay(EGRET_SESSION_DELAY);
120 		out_8(&via[B], in_8(&via[B]) | TIP | TACK);
121 	} else
122 		out_8(&via[B], in_8(&via[B]) & ~(TIP | TACK));
123 }
124 
125 static inline void assert_TACK(void)
126 {
127 	if (mcu_is_egret) {
128 		udelay(EGRET_TACK_NEGATED_DELAY);
129 		out_8(&via[B], in_8(&via[B]) | TACK);
130 	} else
131 		out_8(&via[B], in_8(&via[B]) & ~TACK);
132 }
133 
134 static inline void toggle_TACK(void)
135 {
136 	out_8(&via[B], in_8(&via[B]) ^ TACK);
137 }
138 
139 static inline void negate_TACK(void)
140 {
141 	if (mcu_is_egret) {
142 		udelay(EGRET_TACK_ASSERTED_DELAY);
143 		out_8(&via[B], in_8(&via[B]) & ~TACK);
144 	} else
145 		out_8(&via[B], in_8(&via[B]) | TACK);
146 }
147 
148 static inline void negate_TIP_and_TACK(void)
149 {
150 	if (mcu_is_egret) {
151 		udelay(EGRET_TACK_ASSERTED_DELAY);
152 		out_8(&via[B], in_8(&via[B]) & ~(TIP | TACK));
153 	} else
154 		out_8(&via[B], in_8(&via[B]) | TIP | TACK);
155 }
156 
157 static enum cuda_state {
158     idle,
159     sent_first_byte,
160     sending,
161     reading,
162     read_done,
163     awaiting_reply
164 } cuda_state;
165 
166 static struct adb_request *current_req;
167 static struct adb_request *last_req;
168 static unsigned char cuda_rbuf[16];
169 static unsigned char *reply_ptr;
170 static int reading_reply;
171 static int data_index;
172 static int cuda_irq;
173 #ifdef CONFIG_PPC
174 static struct device_node *vias;
175 #endif
176 static int cuda_fully_inited;
177 
178 #ifdef CONFIG_ADB
179 static int cuda_probe(void);
180 static int cuda_send_request(struct adb_request *req, int sync);
181 static int cuda_adb_autopoll(int devs);
182 static int cuda_reset_adb_bus(void);
183 #endif /* CONFIG_ADB */
184 
185 static int cuda_init_via(void);
186 static void cuda_start(void);
187 static irqreturn_t cuda_interrupt(int irq, void *arg);
188 static void cuda_input(unsigned char *buf, int nb);
189 void cuda_poll(void);
190 static int cuda_write(struct adb_request *req);
191 
192 int cuda_request(struct adb_request *req,
193 		 void (*done)(struct adb_request *), int nbytes, ...);
194 
195 #ifdef CONFIG_ADB
196 struct adb_driver via_cuda_driver = {
197 	.name         = "CUDA",
198 	.probe        = cuda_probe,
199 	.send_request = cuda_send_request,
200 	.autopoll     = cuda_adb_autopoll,
201 	.poll         = cuda_poll,
202 	.reset_bus    = cuda_reset_adb_bus,
203 };
204 #endif /* CONFIG_ADB */
205 
206 #ifdef CONFIG_MAC
207 int __init find_via_cuda(void)
208 {
209     struct adb_request req;
210     int err;
211 
212     if (macintosh_config->adb_type != MAC_ADB_CUDA &&
213         macintosh_config->adb_type != MAC_ADB_EGRET)
214 	return 0;
215 
216     via = via1;
217     cuda_state = idle;
218     mcu_is_egret = macintosh_config->adb_type == MAC_ADB_EGRET;
219 
220     err = cuda_init_via();
221     if (err) {
222 	printk(KERN_ERR "cuda_init_via() failed\n");
223 	via = NULL;
224 	return 0;
225     }
226 
227     /* enable autopoll */
228     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
229     while (!req.complete)
230 	cuda_poll();
231 
232     return 1;
233 }
234 #else
235 int __init find_via_cuda(void)
236 {
237     struct adb_request req;
238     struct resource res;
239     int err;
240 
241     if (vias)
242 	return 1;
243     vias = of_find_node_by_name(NULL, "via-cuda");
244     if (!vias)
245 	return 0;
246 
247     err = of_address_to_resource(vias, 0, &res);
248     if (err) {
249 	    printk(KERN_ERR "via-cuda: Error getting \"reg\" property !\n");
250 	    goto fail;
251     }
252     via = ioremap(res.start, 0x2000);
253     if (via == NULL) {
254 	    printk(KERN_ERR "via-cuda: Can't map address !\n");
255 	    goto fail;
256     }
257 
258     cuda_state = idle;
259     sys_ctrler = SYS_CTRLER_CUDA;
260 
261     err = cuda_init_via();
262     if (err) {
263 	printk(KERN_ERR "cuda_init_via() failed\n");
264 	via = NULL;
265 	return 0;
266     }
267 
268     /* Clear and enable interrupts, but only on PPC. On 68K it's done  */
269     /* for us by the main VIA driver in arch/m68k/mac/via.c        */
270 
271     out_8(&via[IFR], 0x7f);	/* clear interrupts by writing 1s */
272     out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
273 
274     /* enable autopoll */
275     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
276     while (!req.complete)
277 	cuda_poll();
278 
279     return 1;
280 
281  fail:
282     of_node_put(vias);
283     vias = NULL;
284     return 0;
285 }
286 #endif /* !defined CONFIG_MAC */
287 
288 static int __init via_cuda_start(void)
289 {
290     if (via == NULL)
291 	return -ENODEV;
292 
293 #ifdef CONFIG_MAC
294     cuda_irq = IRQ_MAC_ADB;
295 #else
296     cuda_irq = irq_of_parse_and_map(vias, 0);
297     if (!cuda_irq) {
298 	printk(KERN_ERR "via-cuda: can't map interrupts for %pOF\n",
299 	       vias);
300 	return -ENODEV;
301     }
302 #endif
303 
304     if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
305 	printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
306 	return -EAGAIN;
307     }
308 
309     pr_info("Macintosh Cuda and Egret driver.\n");
310 
311     cuda_fully_inited = 1;
312     return 0;
313 }
314 
315 device_initcall(via_cuda_start);
316 
317 #ifdef CONFIG_ADB
318 static int
319 cuda_probe(void)
320 {
321 #ifdef CONFIG_PPC
322     if (sys_ctrler != SYS_CTRLER_CUDA)
323 	return -ENODEV;
324 #else
325     if (macintosh_config->adb_type != MAC_ADB_CUDA &&
326         macintosh_config->adb_type != MAC_ADB_EGRET)
327 	return -ENODEV;
328 #endif
329     if (via == NULL)
330 	return -ENODEV;
331     return 0;
332 }
333 #endif /* CONFIG_ADB */
334 
335 static int __init sync_egret(void)
336 {
337 	if (TREQ_asserted(in_8(&via[B]))) {
338 		/* Complete the inbound transfer */
339 		assert_TIP_and_TACK();
340 		while (1) {
341 			negate_TACK();
342 			mdelay(1);
343 			(void)in_8(&via[SR]);
344 			assert_TACK();
345 			if (!TREQ_asserted(in_8(&via[B])))
346 				break;
347 		}
348 		negate_TIP_and_TACK();
349 	} else if (in_8(&via[B]) & TIP) {
350 		/* Terminate the outbound transfer */
351 		negate_TACK();
352 		assert_TACK();
353 		mdelay(1);
354 		negate_TIP_and_TACK();
355 	}
356 	/* Clear shift register interrupt */
357 	if (in_8(&via[IFR]) & SR_INT)
358 		(void)in_8(&via[SR]);
359 	return 0;
360 }
361 
362 #define WAIT_FOR(cond, what)					\
363     do {                                                        \
364     	int x;							\
365 	for (x = 1000; !(cond); --x) {				\
366 	    if (x == 0) {					\
367 		pr_err("Timeout waiting for " what "\n");	\
368 		return -ENXIO;					\
369 	    }							\
370 	    udelay(100);					\
371 	}							\
372     } while (0)
373 
374 static int
375 __init cuda_init_via(void)
376 {
377 #ifdef CONFIG_PPC
378     out_8(&via[IER], 0x7f);					/* disable interrupts from VIA */
379     (void)in_8(&via[IER]);
380 #else
381     out_8(&via[IER], SR_INT);					/* disable SR interrupt from VIA */
382 #endif
383 
384     out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ);	/* TACK & TIP out */
385     out_8(&via[ACR], (in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT);	/* SR data in */
386     (void)in_8(&via[SR]);					/* clear any left-over data */
387 
388     if (mcu_is_egret)
389 	return sync_egret();
390 
391     negate_TIP_and_TACK();
392 
393     /* delay 4ms and then clear any pending interrupt */
394     mdelay(4);
395     (void)in_8(&via[SR]);
396     out_8(&via[IFR], SR_INT);
397 
398     /* sync with the CUDA - assert TACK without TIP */
399     assert_TACK();
400 
401     /* wait for the CUDA to assert TREQ in response */
402     WAIT_FOR(TREQ_asserted(in_8(&via[B])), "CUDA response to sync");
403 
404     /* wait for the interrupt and then clear it */
405     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
406     (void)in_8(&via[SR]);
407     out_8(&via[IFR], SR_INT);
408 
409     /* finish the sync by negating TACK */
410     negate_TACK();
411 
412     /* wait for the CUDA to negate TREQ and the corresponding interrupt */
413     WAIT_FOR(!TREQ_asserted(in_8(&via[B])), "CUDA response to sync (3)");
414     WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
415     (void)in_8(&via[SR]);
416     out_8(&via[IFR], SR_INT);
417 
418     return 0;
419 }
420 
421 #ifdef CONFIG_ADB
422 /* Send an ADB command */
423 static int
424 cuda_send_request(struct adb_request *req, int sync)
425 {
426     int i;
427 
428     if ((via == NULL) || !cuda_fully_inited) {
429 	req->complete = 1;
430 	return -ENXIO;
431     }
432 
433     req->reply_expected = 1;
434 
435     i = cuda_write(req);
436     if (i)
437 	return i;
438 
439     if (sync) {
440 	while (!req->complete)
441 	    cuda_poll();
442     }
443     return 0;
444 }
445 
446 
447 /* Enable/disable autopolling */
448 static int
449 cuda_adb_autopoll(int devs)
450 {
451     struct adb_request req;
452 
453     if ((via == NULL) || !cuda_fully_inited)
454 	return -ENXIO;
455 
456     cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
457     while (!req.complete)
458 	cuda_poll();
459     return 0;
460 }
461 
462 /* Reset adb bus - how do we do this?? */
463 static int
464 cuda_reset_adb_bus(void)
465 {
466     struct adb_request req;
467 
468     if ((via == NULL) || !cuda_fully_inited)
469 	return -ENXIO;
470 
471     cuda_request(&req, NULL, 2, ADB_PACKET, 0);		/* maybe? */
472     while (!req.complete)
473 	cuda_poll();
474     return 0;
475 }
476 #endif /* CONFIG_ADB */
477 
478 /* Construct and send a cuda request */
479 int
480 cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
481 	     int nbytes, ...)
482 {
483     va_list list;
484     int i;
485 
486     if (via == NULL) {
487 	req->complete = 1;
488 	return -ENXIO;
489     }
490 
491     req->nbytes = nbytes;
492     req->done = done;
493     va_start(list, nbytes);
494     for (i = 0; i < nbytes; ++i)
495 	req->data[i] = va_arg(list, int);
496     va_end(list);
497     req->reply_expected = 1;
498     return cuda_write(req);
499 }
500 EXPORT_SYMBOL(cuda_request);
501 
502 static int
503 cuda_write(struct adb_request *req)
504 {
505     unsigned long flags;
506 
507     if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
508 	req->complete = 1;
509 	return -EINVAL;
510     }
511     req->next = NULL;
512     req->sent = 0;
513     req->complete = 0;
514     req->reply_len = 0;
515 
516     spin_lock_irqsave(&cuda_lock, flags);
517     if (current_req) {
518 	last_req->next = req;
519 	last_req = req;
520     } else {
521 	current_req = req;
522 	last_req = req;
523 	if (cuda_state == idle)
524 	    cuda_start();
525     }
526     spin_unlock_irqrestore(&cuda_lock, flags);
527 
528     return 0;
529 }
530 
531 static void
532 cuda_start(void)
533 {
534     /* assert cuda_state == idle */
535     if (current_req == NULL)
536 	return;
537     data_index = 0;
538     if (TREQ_asserted(in_8(&via[B])))
539 	return;			/* a byte is coming in from the CUDA */
540 
541     /* set the shift register to shift out and send a byte */
542     out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
543     out_8(&via[SR], current_req->data[data_index++]);
544     if (mcu_is_egret)
545 	assert_TIP_and_TACK();
546     else
547 	assert_TIP();
548     cuda_state = sent_first_byte;
549 }
550 
551 void
552 cuda_poll(void)
553 {
554 	cuda_interrupt(0, NULL);
555 }
556 EXPORT_SYMBOL(cuda_poll);
557 
558 #define ARRAY_FULL(a, p)	((p) - (a) == ARRAY_SIZE(a))
559 
560 static irqreturn_t
561 cuda_interrupt(int irq, void *arg)
562 {
563     unsigned long flags;
564     u8 status;
565     struct adb_request *req = NULL;
566     unsigned char ibuf[16];
567     int ibuf_len = 0;
568     int complete = 0;
569     bool full;
570 
571     spin_lock_irqsave(&cuda_lock, flags);
572 
573     /* On powermacs, this handler is registered for the VIA IRQ. But they use
574      * just the shift register IRQ -- other VIA interrupt sources are disabled.
575      * On m68k macs, the VIA IRQ sources are dispatched individually. Unless
576      * we are polling, the shift register IRQ flag has already been cleared.
577      */
578 
579 #ifdef CONFIG_MAC
580     if (!arg)
581 #endif
582     {
583         if ((in_8(&via[IFR]) & SR_INT) == 0) {
584             spin_unlock_irqrestore(&cuda_lock, flags);
585             return IRQ_NONE;
586         } else {
587             out_8(&via[IFR], SR_INT);
588         }
589     }
590 
591     status = in_8(&via[B]) & (TIP | TACK | TREQ);
592 
593     switch (cuda_state) {
594     case idle:
595 	/* System controller has unsolicited data for us */
596 	(void)in_8(&via[SR]);
597 idle_state:
598 	assert_TIP();
599 	cuda_state = reading;
600 	reply_ptr = cuda_rbuf;
601 	reading_reply = 0;
602 	break;
603 
604     case awaiting_reply:
605 	/* System controller has reply data for us */
606 	(void)in_8(&via[SR]);
607 	assert_TIP();
608 	cuda_state = reading;
609 	reply_ptr = current_req->reply;
610 	reading_reply = 1;
611 	break;
612 
613     case sent_first_byte:
614 	if (TREQ_asserted(status)) {
615 	    /* collision */
616 	    out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
617 	    (void)in_8(&via[SR]);
618 	    negate_TIP_and_TACK();
619 	    cuda_state = idle;
620 	    /* Egret does not raise an "aborted" interrupt */
621 	    if (mcu_is_egret)
622 		goto idle_state;
623 	} else {
624 	    out_8(&via[SR], current_req->data[data_index++]);
625 	    toggle_TACK();
626 	    if (mcu_is_egret)
627 		assert_TACK();
628 	    cuda_state = sending;
629 	}
630 	break;
631 
632     case sending:
633 	req = current_req;
634 	if (data_index >= req->nbytes) {
635 	    out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
636 	    (void)in_8(&via[SR]);
637 	    negate_TIP_and_TACK();
638 	    req->sent = 1;
639 	    if (req->reply_expected) {
640 		cuda_state = awaiting_reply;
641 	    } else {
642 		current_req = req->next;
643 		complete = 1;
644 		/* not sure about this */
645 		cuda_state = idle;
646 		cuda_start();
647 	    }
648 	} else {
649 	    out_8(&via[SR], req->data[data_index++]);
650 	    toggle_TACK();
651 	    if (mcu_is_egret)
652 		assert_TACK();
653 	}
654 	break;
655 
656     case reading:
657 	full = reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr)
658 	                     : ARRAY_FULL(cuda_rbuf, reply_ptr);
659 	if (full)
660 	    (void)in_8(&via[SR]);
661 	else
662 	    *reply_ptr++ = in_8(&via[SR]);
663 	if (!TREQ_asserted(status) || full) {
664 	    if (mcu_is_egret)
665 		assert_TACK();
666 	    /* that's all folks */
667 	    negate_TIP_and_TACK();
668 	    cuda_state = read_done;
669 	    /* Egret does not raise a "read done" interrupt */
670 	    if (mcu_is_egret)
671 		goto read_done_state;
672 	} else {
673 	    toggle_TACK();
674 	    if (mcu_is_egret)
675 		negate_TACK();
676 	}
677 	break;
678 
679     case read_done:
680 	(void)in_8(&via[SR]);
681 read_done_state:
682 	if (reading_reply) {
683 	    req = current_req;
684 	    req->reply_len = reply_ptr - req->reply;
685 	    if (req->data[0] == ADB_PACKET) {
686 		/* Have to adjust the reply from ADB commands */
687 		if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
688 		    /* the 0x2 bit indicates no response */
689 		    req->reply_len = 0;
690 		} else {
691 		    /* leave just the command and result bytes in the reply */
692 		    req->reply_len -= 2;
693 		    memmove(req->reply, req->reply + 2, req->reply_len);
694 		}
695 	    }
696 	    current_req = req->next;
697 	    complete = 1;
698 	    reading_reply = 0;
699 	} else {
700 	    /* This is tricky. We must break the spinlock to call
701 	     * cuda_input. However, doing so means we might get
702 	     * re-entered from another CPU getting an interrupt
703 	     * or calling cuda_poll(). I ended up using the stack
704 	     * (it's only for 16 bytes) and moving the actual
705 	     * call to cuda_input to outside of the lock.
706 	     */
707 	    ibuf_len = reply_ptr - cuda_rbuf;
708 	    memcpy(ibuf, cuda_rbuf, ibuf_len);
709 	}
710 	reply_ptr = cuda_rbuf;
711 	cuda_state = idle;
712 	cuda_start();
713 	if (cuda_state == idle && TREQ_asserted(in_8(&via[B]))) {
714 	    assert_TIP();
715 	    cuda_state = reading;
716 	}
717 	break;
718 
719     default:
720 	pr_err("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
721     }
722     spin_unlock_irqrestore(&cuda_lock, flags);
723     if (complete && req) {
724     	void (*done)(struct adb_request *) = req->done;
725     	mb();
726     	req->complete = 1;
727     	/* Here, we assume that if the request has a done member, the
728     	 * struct request will survive to setting req->complete to 1
729     	 */
730     	if (done)
731 		(*done)(req);
732     }
733     if (ibuf_len)
734 	cuda_input(ibuf, ibuf_len);
735     return IRQ_HANDLED;
736 }
737 
738 static void
739 cuda_input(unsigned char *buf, int nb)
740 {
741     switch (buf[0]) {
742     case ADB_PACKET:
743 #ifdef CONFIG_XMON
744 	if (nb == 5 && buf[2] == 0x2c) {
745 	    extern int xmon_wants_key, xmon_adb_keycode;
746 	    if (xmon_wants_key) {
747 		xmon_adb_keycode = buf[3];
748 		return;
749 	    }
750 	}
751 #endif /* CONFIG_XMON */
752 #ifdef CONFIG_ADB
753 	adb_input(buf+2, nb-2, buf[1] & 0x40);
754 #endif /* CONFIG_ADB */
755 	break;
756 
757     case TIMER_PACKET:
758 	/* Egret sends these periodically. Might be useful as a 'heartbeat'
759 	 * to trigger a recovery for the VIA shift register errata.
760 	 */
761 	break;
762 
763     default:
764 	print_hex_dump(KERN_INFO, "cuda_input: ", DUMP_PREFIX_NONE, 32, 1,
765 	               buf, nb, false);
766     }
767 }
768 
769 /* Offset between Unix time (1970-based) and Mac time (1904-based) */
770 #define RTC_OFFSET	2082844800
771 
772 time64_t cuda_get_time(void)
773 {
774 	struct adb_request req;
775 	u32 now;
776 
777 	if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
778 		return 0;
779 	while (!req.complete)
780 		cuda_poll();
781 	if (req.reply_len != 7)
782 		pr_err("%s: got %d byte reply\n", __func__, req.reply_len);
783 	now = (req.reply[3] << 24) + (req.reply[4] << 16) +
784 	      (req.reply[5] << 8) + req.reply[6];
785 	return (time64_t)now - RTC_OFFSET;
786 }
787 
788 int cuda_set_rtc_time(struct rtc_time *tm)
789 {
790 	u32 now;
791 	struct adb_request req;
792 
793 	now = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET);
794 	if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
795 	                 now >> 24, now >> 16, now >> 8, now) < 0)
796 		return -ENXIO;
797 	while (!req.complete)
798 		cuda_poll();
799 	if ((req.reply_len != 3) && (req.reply_len != 7))
800 		pr_err("%s: got %d byte reply\n", __func__, req.reply_len);
801 	return 0;
802 }
803