xref: /openbmc/linux/arch/m68k/mac/misc.c (revision ccb01374)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Miscellaneous Mac68K-specific stuff
4  */
5 
6 #include <linux/types.h>
7 #include <linux/errno.h>
8 #include <linux/kernel.h>
9 #include <linux/delay.h>
10 #include <linux/sched.h>
11 #include <linux/time.h>
12 #include <linux/rtc.h>
13 #include <linux/mm.h>
14 
15 #include <linux/adb.h>
16 #include <linux/cuda.h>
17 #include <linux/pmu.h>
18 
19 #include <linux/uaccess.h>
20 #include <asm/io.h>
21 #include <asm/segment.h>
22 #include <asm/setup.h>
23 #include <asm/macintosh.h>
24 #include <asm/mac_via.h>
25 #include <asm/mac_oss.h>
26 
27 #include <asm/machdep.h>
28 
29 /*
30  * Offset between Unix time (1970-based) and Mac time (1904-based). Cuda and PMU
31  * times wrap in 2040. If we need to handle later times, the read_time functions
32  * need to be changed to interpret wrapped times as post-2040.
33  */
34 
35 #define RTC_OFFSET 2082844800
36 
37 static void (*rom_reset)(void);
38 
39 #ifdef CONFIG_ADB_CUDA
40 static __u8 cuda_read_pram(int offset)
41 {
42 	struct adb_request req;
43 
44 	if (cuda_request(&req, NULL, 4, CUDA_PACKET, CUDA_GET_PRAM,
45 			 (offset >> 8) & 0xFF, offset & 0xFF) < 0)
46 		return 0;
47 	while (!req.complete)
48 		cuda_poll();
49 	return req.reply[3];
50 }
51 
52 static void cuda_write_pram(int offset, __u8 data)
53 {
54 	struct adb_request req;
55 
56 	if (cuda_request(&req, NULL, 5, CUDA_PACKET, CUDA_SET_PRAM,
57 			 (offset >> 8) & 0xFF, offset & 0xFF, data) < 0)
58 		return;
59 	while (!req.complete)
60 		cuda_poll();
61 }
62 #endif /* CONFIG_ADB_CUDA */
63 
64 #ifdef CONFIG_ADB_PMU
65 static __u8 pmu_read_pram(int offset)
66 {
67 	struct adb_request req;
68 
69 	if (pmu_request(&req, NULL, 3, PMU_READ_NVRAM,
70 			(offset >> 8) & 0xFF, offset & 0xFF) < 0)
71 		return 0;
72 	while (!req.complete)
73 		pmu_poll();
74 	return req.reply[3];
75 }
76 
77 static void pmu_write_pram(int offset, __u8 data)
78 {
79 	struct adb_request req;
80 
81 	if (pmu_request(&req, NULL, 4, PMU_WRITE_NVRAM,
82 			(offset >> 8) & 0xFF, offset & 0xFF, data) < 0)
83 		return;
84 	while (!req.complete)
85 		pmu_poll();
86 }
87 #endif /* CONFIG_ADB_PMU */
88 
89 /*
90  * VIA PRAM/RTC access routines
91  *
92  * Must be called with interrupts disabled and
93  * the RTC should be enabled.
94  */
95 
96 static __u8 via_pram_readbyte(void)
97 {
98 	int i, reg;
99 	__u8 data;
100 
101 	reg = via1[vBufB] & ~VIA1B_vRTCClk;
102 
103 	/* Set the RTC data line to be an input. */
104 
105 	via1[vDirB] &= ~VIA1B_vRTCData;
106 
107 	/* The bits of the byte come out in MSB order */
108 
109 	data = 0;
110 	for (i = 0 ; i < 8 ; i++) {
111 		via1[vBufB] = reg;
112 		via1[vBufB] = reg | VIA1B_vRTCClk;
113 		data = (data << 1) | (via1[vBufB] & VIA1B_vRTCData);
114 	}
115 
116 	/* Return RTC data line to output state */
117 
118 	via1[vDirB] |= VIA1B_vRTCData;
119 
120 	return data;
121 }
122 
123 static void via_pram_writebyte(__u8 data)
124 {
125 	int i, reg, bit;
126 
127 	reg = via1[vBufB] & ~(VIA1B_vRTCClk | VIA1B_vRTCData);
128 
129 	/* The bits of the byte go in in MSB order */
130 
131 	for (i = 0 ; i < 8 ; i++) {
132 		bit = data & 0x80? 1 : 0;
133 		data <<= 1;
134 		via1[vBufB] = reg | bit;
135 		via1[vBufB] = reg | bit | VIA1B_vRTCClk;
136 	}
137 }
138 
139 /*
140  * Execute a VIA PRAM/RTC command. For read commands
141  * data should point to a one-byte buffer for the
142  * resulting data. For write commands it should point
143  * to the data byte to for the command.
144  *
145  * This function disables all interrupts while running.
146  */
147 
148 static void via_pram_command(int command, __u8 *data)
149 {
150 	unsigned long flags;
151 	int is_read;
152 
153 	local_irq_save(flags);
154 
155 	/* Enable the RTC and make sure the strobe line is high */
156 
157 	via1[vBufB] = (via1[vBufB] | VIA1B_vRTCClk) & ~VIA1B_vRTCEnb;
158 
159 	if (command & 0xFF00) {		/* extended (two-byte) command */
160 		via_pram_writebyte((command & 0xFF00) >> 8);
161 		via_pram_writebyte(command & 0xFF);
162 		is_read = command & 0x8000;
163 	} else {			/* one-byte command */
164 		via_pram_writebyte(command);
165 		is_read = command & 0x80;
166 	}
167 	if (is_read) {
168 		*data = via_pram_readbyte();
169 	} else {
170 		via_pram_writebyte(*data);
171 	}
172 
173 	/* All done, disable the RTC */
174 
175 	via1[vBufB] |= VIA1B_vRTCEnb;
176 
177 	local_irq_restore(flags);
178 }
179 
180 static __u8 via_read_pram(int offset)
181 {
182 	return 0;
183 }
184 
185 static void via_write_pram(int offset, __u8 data)
186 {
187 }
188 
189 /*
190  * Return the current time in seconds since January 1, 1904.
191  *
192  * This only works on machines with the VIA-based PRAM/RTC, which
193  * is basically any machine with Mac II-style ADB.
194  */
195 
196 static time64_t via_read_time(void)
197 {
198 	union {
199 		__u8 cdata[4];
200 		__u32 idata;
201 	} result, last_result;
202 	int count = 1;
203 
204 	via_pram_command(0x81, &last_result.cdata[3]);
205 	via_pram_command(0x85, &last_result.cdata[2]);
206 	via_pram_command(0x89, &last_result.cdata[1]);
207 	via_pram_command(0x8D, &last_result.cdata[0]);
208 
209 	/*
210 	 * The NetBSD guys say to loop until you get the same reading
211 	 * twice in a row.
212 	 */
213 
214 	while (1) {
215 		via_pram_command(0x81, &result.cdata[3]);
216 		via_pram_command(0x85, &result.cdata[2]);
217 		via_pram_command(0x89, &result.cdata[1]);
218 		via_pram_command(0x8D, &result.cdata[0]);
219 
220 		if (result.idata == last_result.idata)
221 			return (time64_t)result.idata - RTC_OFFSET;
222 
223 		if (++count > 10)
224 			break;
225 
226 		last_result.idata = result.idata;
227 	}
228 
229 	pr_err("%s: failed to read a stable value; got 0x%08x then 0x%08x\n",
230 	       __func__, last_result.idata, result.idata);
231 
232 	return 0;
233 }
234 
235 /*
236  * Set the current time to a number of seconds since January 1, 1904.
237  *
238  * This only works on machines with the VIA-based PRAM/RTC, which
239  * is basically any machine with Mac II-style ADB.
240  */
241 
242 static void via_set_rtc_time(struct rtc_time *tm)
243 {
244 	union {
245 		__u8 cdata[4];
246 		__u32 idata;
247 	} data;
248 	__u8 temp;
249 	time64_t time;
250 
251 	time = mktime64(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
252 	                tm->tm_hour, tm->tm_min, tm->tm_sec);
253 
254 	/* Clear the write protect bit */
255 
256 	temp = 0x55;
257 	via_pram_command(0x35, &temp);
258 
259 	data.idata = lower_32_bits(time + RTC_OFFSET);
260 	via_pram_command(0x01, &data.cdata[3]);
261 	via_pram_command(0x05, &data.cdata[2]);
262 	via_pram_command(0x09, &data.cdata[1]);
263 	via_pram_command(0x0D, &data.cdata[0]);
264 
265 	/* Set the write protect bit */
266 
267 	temp = 0xD5;
268 	via_pram_command(0x35, &temp);
269 }
270 
271 static void via_shutdown(void)
272 {
273 	if (rbv_present) {
274 		via2[rBufB] &= ~0x04;
275 	} else {
276 		/* Direction of vDirB is output */
277 		via2[vDirB] |= 0x04;
278 		/* Send a value of 0 on that line */
279 		via2[vBufB] &= ~0x04;
280 		mdelay(1000);
281 	}
282 }
283 
284 static void oss_shutdown(void)
285 {
286 	oss->rom_ctrl = OSS_POWEROFF;
287 }
288 
289 #ifdef CONFIG_ADB_CUDA
290 static void cuda_restart(void)
291 {
292 	struct adb_request req;
293 
294 	if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_RESET_SYSTEM) < 0)
295 		return;
296 	while (!req.complete)
297 		cuda_poll();
298 }
299 
300 static void cuda_shutdown(void)
301 {
302 	struct adb_request req;
303 
304 	if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_POWERDOWN) < 0)
305 		return;
306 
307 	/* Avoid infinite polling loop when PSU is not under Cuda control */
308 	switch (macintosh_config->ident) {
309 	case MAC_MODEL_C660:
310 	case MAC_MODEL_Q605:
311 	case MAC_MODEL_Q605_ACC:
312 	case MAC_MODEL_P475:
313 	case MAC_MODEL_P475F:
314 		return;
315 	}
316 
317 	while (!req.complete)
318 		cuda_poll();
319 }
320 #endif /* CONFIG_ADB_CUDA */
321 
322 /*
323  *-------------------------------------------------------------------
324  * Below this point are the generic routines; they'll dispatch to the
325  * correct routine for the hardware on which we're running.
326  *-------------------------------------------------------------------
327  */
328 
329 void mac_pram_read(int offset, __u8 *buffer, int len)
330 {
331 	__u8 (*func)(int);
332 	int i;
333 
334 	switch (macintosh_config->adb_type) {
335 	case MAC_ADB_IOP:
336 	case MAC_ADB_II:
337 	case MAC_ADB_PB1:
338 		func = via_read_pram;
339 		break;
340 #ifdef CONFIG_ADB_CUDA
341 	case MAC_ADB_EGRET:
342 	case MAC_ADB_CUDA:
343 		func = cuda_read_pram;
344 		break;
345 #endif
346 #ifdef CONFIG_ADB_PMU
347 	case MAC_ADB_PB2:
348 		func = pmu_read_pram;
349 		break;
350 #endif
351 	default:
352 		return;
353 	}
354 	for (i = 0 ; i < len ; i++) {
355 		buffer[i] = (*func)(offset++);
356 	}
357 }
358 
359 void mac_pram_write(int offset, __u8 *buffer, int len)
360 {
361 	void (*func)(int, __u8);
362 	int i;
363 
364 	switch (macintosh_config->adb_type) {
365 	case MAC_ADB_IOP:
366 	case MAC_ADB_II:
367 	case MAC_ADB_PB1:
368 		func = via_write_pram;
369 		break;
370 #ifdef CONFIG_ADB_CUDA
371 	case MAC_ADB_EGRET:
372 	case MAC_ADB_CUDA:
373 		func = cuda_write_pram;
374 		break;
375 #endif
376 #ifdef CONFIG_ADB_PMU
377 	case MAC_ADB_PB2:
378 		func = pmu_write_pram;
379 		break;
380 #endif
381 	default:
382 		return;
383 	}
384 	for (i = 0 ; i < len ; i++) {
385 		(*func)(offset++, buffer[i]);
386 	}
387 }
388 
389 void mac_poweroff(void)
390 {
391 	if (oss_present) {
392 		oss_shutdown();
393 	} else if (macintosh_config->adb_type == MAC_ADB_II) {
394 		via_shutdown();
395 #ifdef CONFIG_ADB_CUDA
396 	} else if (macintosh_config->adb_type == MAC_ADB_EGRET ||
397 	           macintosh_config->adb_type == MAC_ADB_CUDA) {
398 		cuda_shutdown();
399 #endif
400 #ifdef CONFIG_ADB_PMU
401 	} else if (macintosh_config->adb_type == MAC_ADB_PB2) {
402 		pmu_shutdown();
403 #endif
404 	}
405 
406 	pr_crit("It is now safe to turn off your Macintosh.\n");
407 	local_irq_disable();
408 	while(1);
409 }
410 
411 void mac_reset(void)
412 {
413 	if (macintosh_config->adb_type == MAC_ADB_II) {
414 		unsigned long flags;
415 
416 		/* need ROMBASE in booter */
417 		/* indeed, plus need to MAP THE ROM !! */
418 
419 		if (mac_bi_data.rombase == 0)
420 			mac_bi_data.rombase = 0x40800000;
421 
422 		/* works on some */
423 		rom_reset = (void *) (mac_bi_data.rombase + 0xa);
424 
425 		if (macintosh_config->ident == MAC_MODEL_SE30) {
426 			/*
427 			 * MSch: Machines known to crash on ROM reset ...
428 			 */
429 		} else {
430 			local_irq_save(flags);
431 
432 			rom_reset();
433 
434 			local_irq_restore(flags);
435 		}
436 #ifdef CONFIG_ADB_CUDA
437 	} else if (macintosh_config->adb_type == MAC_ADB_EGRET ||
438 	           macintosh_config->adb_type == MAC_ADB_CUDA) {
439 		cuda_restart();
440 #endif
441 #ifdef CONFIG_ADB_PMU
442 	} else if (macintosh_config->adb_type == MAC_ADB_PB2) {
443 		pmu_restart();
444 #endif
445 	} else if (CPU_IS_030) {
446 
447 		/* 030-specific reset routine.  The idea is general, but the
448 		 * specific registers to reset are '030-specific.  Until I
449 		 * have a non-030 machine, I can't test anything else.
450 		 *  -- C. Scott Ananian <cananian@alumni.princeton.edu>
451 		 */
452 
453 		unsigned long rombase = 0x40000000;
454 
455 		/* make a 1-to-1 mapping, using the transparent tran. reg. */
456 		unsigned long virt = (unsigned long) mac_reset;
457 		unsigned long phys = virt_to_phys(mac_reset);
458 		unsigned long addr = (phys&0xFF000000)|0x8777;
459 		unsigned long offset = phys-virt;
460 
461 		local_irq_disable(); /* lets not screw this up, ok? */
462 		__asm__ __volatile__(".chip 68030\n\t"
463 				     "pmove %0,%/tt0\n\t"
464 				     ".chip 68k"
465 				     : : "m" (addr));
466 		/* Now jump to physical address so we can disable MMU */
467 		__asm__ __volatile__(
468 		    ".chip 68030\n\t"
469 		    "lea %/pc@(1f),%/a0\n\t"
470 		    "addl %0,%/a0\n\t"/* fixup target address and stack ptr */
471 		    "addl %0,%/sp\n\t"
472 		    "pflusha\n\t"
473 		    "jmp %/a0@\n\t" /* jump into physical memory */
474 		    "0:.long 0\n\t" /* a constant zero. */
475 		    /* OK.  Now reset everything and jump to reset vector. */
476 		    "1:\n\t"
477 		    "lea %/pc@(0b),%/a0\n\t"
478 		    "pmove %/a0@, %/tc\n\t" /* disable mmu */
479 		    "pmove %/a0@, %/tt0\n\t" /* disable tt0 */
480 		    "pmove %/a0@, %/tt1\n\t" /* disable tt1 */
481 		    "movel #0, %/a0\n\t"
482 		    "movec %/a0, %/vbr\n\t" /* clear vector base register */
483 		    "movec %/a0, %/cacr\n\t" /* disable caches */
484 		    "movel #0x0808,%/a0\n\t"
485 		    "movec %/a0, %/cacr\n\t" /* flush i&d caches */
486 		    "movew #0x2700,%/sr\n\t" /* set up status register */
487 		    "movel %1@(0x0),%/a0\n\t"/* load interrupt stack pointer */
488 		    "movec %/a0, %/isp\n\t"
489 		    "movel %1@(0x4),%/a0\n\t" /* load reset vector */
490 		    "reset\n\t" /* reset external devices */
491 		    "jmp %/a0@\n\t" /* jump to the reset vector */
492 		    ".chip 68k"
493 		    : : "r" (offset), "a" (rombase) : "a0");
494 	}
495 
496 	/* should never get here */
497 	pr_crit("Restart failed. Please restart manually.\n");
498 	local_irq_disable();
499 	while(1);
500 }
501 
502 /*
503  * This function translates seconds since 1970 into a proper date.
504  *
505  * Algorithm cribbed from glibc2.1, __offtime().
506  *
507  * This is roughly same as rtc_time64_to_tm(), which we should probably
508  * use here, but it's only available when CONFIG_RTC_LIB is enabled.
509  */
510 #define SECS_PER_MINUTE (60)
511 #define SECS_PER_HOUR  (SECS_PER_MINUTE * 60)
512 #define SECS_PER_DAY   (SECS_PER_HOUR * 24)
513 
514 static void unmktime(time64_t time, long offset,
515 		     int *yearp, int *monp, int *dayp,
516 		     int *hourp, int *minp, int *secp)
517 {
518         /* How many days come before each month (0-12).  */
519 	static const unsigned short int __mon_yday[2][13] =
520 	{
521 		/* Normal years.  */
522 		{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
523 		/* Leap years.  */
524 		{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
525 	};
526 	int days, rem, y, wday, yday;
527 	const unsigned short int *ip;
528 
529 	days = div_u64_rem(time, SECS_PER_DAY, &rem);
530 	rem += offset;
531 	while (rem < 0) {
532 		rem += SECS_PER_DAY;
533 		--days;
534 	}
535 	while (rem >= SECS_PER_DAY) {
536 		rem -= SECS_PER_DAY;
537 		++days;
538 	}
539 	*hourp = rem / SECS_PER_HOUR;
540 	rem %= SECS_PER_HOUR;
541 	*minp = rem / SECS_PER_MINUTE;
542 	*secp = rem % SECS_PER_MINUTE;
543 	/* January 1, 1970 was a Thursday. */
544 	wday = (4 + days) % 7; /* Day in the week. Not currently used */
545 	if (wday < 0) wday += 7;
546 	y = 1970;
547 
548 #define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
549 #define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
550 #define __isleap(year)	\
551   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
552 
553 	while (days < 0 || days >= (__isleap (y) ? 366 : 365))
554 	{
555 		/* Guess a corrected year, assuming 365 days per year.  */
556 		long int yg = y + days / 365 - (days % 365 < 0);
557 
558 		/* Adjust DAYS and Y to match the guessed year.  */
559 		days -= (yg - y) * 365 +
560 			LEAPS_THRU_END_OF(yg - 1) - LEAPS_THRU_END_OF(y - 1);
561 		y = yg;
562 	}
563 	*yearp = y - 1900;
564 	yday = days; /* day in the year.  Not currently used. */
565 	ip = __mon_yday[__isleap(y)];
566 	for (y = 11; days < (long int) ip[y]; --y)
567 		continue;
568 	days -= ip[y];
569 	*monp = y;
570 	*dayp = days + 1; /* day in the month */
571 	return;
572 }
573 
574 /*
575  * Read/write the hardware clock.
576  */
577 
578 int mac_hwclk(int op, struct rtc_time *t)
579 {
580 	time64_t now;
581 
582 	if (!op) { /* read */
583 		switch (macintosh_config->adb_type) {
584 		case MAC_ADB_IOP:
585 		case MAC_ADB_II:
586 		case MAC_ADB_PB1:
587 			now = via_read_time();
588 			break;
589 #ifdef CONFIG_ADB_CUDA
590 		case MAC_ADB_EGRET:
591 		case MAC_ADB_CUDA:
592 			now = cuda_get_time();
593 			break;
594 #endif
595 #ifdef CONFIG_ADB_PMU
596 		case MAC_ADB_PB2:
597 			now = pmu_get_time();
598 			break;
599 #endif
600 		default:
601 			now = 0;
602 		}
603 
604 		t->tm_wday = 0;
605 		unmktime(now, 0,
606 			 &t->tm_year, &t->tm_mon, &t->tm_mday,
607 			 &t->tm_hour, &t->tm_min, &t->tm_sec);
608 		pr_debug("%s: read %ptR\n", __func__, t);
609 	} else { /* write */
610 		pr_debug("%s: tried to write %ptR\n", __func__, t);
611 
612 		switch (macintosh_config->adb_type) {
613 		case MAC_ADB_IOP:
614 		case MAC_ADB_II:
615 		case MAC_ADB_PB1:
616 			via_set_rtc_time(t);
617 			break;
618 #ifdef CONFIG_ADB_CUDA
619 		case MAC_ADB_EGRET:
620 		case MAC_ADB_CUDA:
621 			cuda_set_rtc_time(t);
622 			break;
623 #endif
624 #ifdef CONFIG_ADB_PMU
625 		case MAC_ADB_PB2:
626 			pmu_set_rtc_time(t);
627 			break;
628 #endif
629 		default:
630 			return -ENODEV;
631 		}
632 	}
633 	return 0;
634 }
635