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
35static volatile unsigned char __iomem *via;
36static 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
99static bool mcu_is_egret;
100#endif
101
102static inline bool TREQ_asserted(u8 portb)
103{
104 return !(portb & TREQ);
105}
106
107static 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
116static 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
125static 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
134static inline void toggle_TACK(void)
135{
136 out_8(&via[B], in_8(&via[B]) ^ TACK);
137}
138
139static 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
148static 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
157static enum cuda_state {
158 idle,
159 sent_first_byte,
160 sending,
161 reading,
162 read_done,
163 awaiting_reply
164} cuda_state;
165
166static struct adb_request *current_req;
167static struct adb_request *last_req;
168static unsigned char cuda_rbuf[16];
169static unsigned char *reply_ptr;
170static int reading_reply;
171static int data_index;
172static int cuda_irq;
173#ifdef CONFIG_PPC
174static struct device_node *vias;
175#endif
176static int cuda_fully_inited;
177
178#ifdef CONFIG_ADB
179static int cuda_probe(void);
180static int cuda_send_request(struct adb_request *req, int sync);
181static int cuda_adb_autopoll(int devs);
182static int cuda_reset_adb_bus(void);
183#endif /* CONFIG_ADB */
184
185static int cuda_init_via(void);
186static void cuda_start(void);
187static irqreturn_t cuda_interrupt(int irq, void *arg);
188static void cuda_input(unsigned char *buf, int nb);
189void cuda_poll(void);
190static int cuda_write(struct adb_request *req);
191
192int cuda_request(struct adb_request *req,
193 void (*done)(struct adb_request *), int nbytes, ...);
194
195#ifdef CONFIG_ADB
196struct 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
207int __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
235int __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, name: "via-cuda");
244 if (!vias)
245 return 0;
246
247 err = of_address_to_resource(dev: vias, index: 0, r: &res);
248 if (err) {
249 printk(KERN_ERR "via-cuda: Error getting \"reg\" property !\n");
250 goto fail;
251 }
252 via = ioremap(offset: res.start, size: 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: &req, NULL, nbytes: 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
276 while (!req.complete)
277 cuda_poll();
278
279 return 1;
280
281 fail:
282 of_node_put(node: vias);
283 vias = NULL;
284 return 0;
285}
286#endif /* !defined CONFIG_MAC */
287
288static 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(node: vias, index: 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(irq: cuda_irq, handler: cuda_interrupt, flags: 0, name: "ADB", dev: 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
315device_initcall(via_cuda_start);
316
317#ifdef CONFIG_ADB
318static int
319cuda_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
335static int __init sync_egret(void)
336{
337 if (TREQ_asserted(portb: 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(portb: 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
374static 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 */
423static int
424cuda_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 */
448static int
449cuda_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?? */
463static int
464cuda_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 */
479int
480cuda_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}
500EXPORT_SYMBOL(cuda_request);
501
502static int
503cuda_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(lock: &cuda_lock, flags);
527
528 return 0;
529}
530
531static void
532cuda_start(void)
533{
534 /* assert cuda_state == idle */
535 if (current_req == NULL)
536 return;
537 data_index = 0;
538 if (TREQ_asserted(portb: 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
551void
552cuda_poll(void)
553{
554 cuda_interrupt(irq: 0, NULL);
555}
556EXPORT_SYMBOL(cuda_poll);
557
558#define ARRAY_FULL(a, p) ((p) - (a) == ARRAY_SIZE(a))
559
560static irqreturn_t
561cuda_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(lock: &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]);
597idle_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(portb: 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(portb: 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]);
681read_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(portb: 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(lock: &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(buf: ibuf, nb: ibuf_len);
735 return IRQ_HANDLED;
736}
737
738static void
739cuda_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, prefix_str: "cuda_input: ", prefix_type: DUMP_PREFIX_NONE, rowsize: 32, groupsize: 1,
765 buf, len: nb, ascii: false);
766 }
767}
768
769/* Offset between Unix time (1970-based) and Mac time (1904-based) */
770#define RTC_OFFSET 2082844800
771
772time64_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
788int 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

source code of linux/drivers/macintosh/via-cuda.c