clock.c revision 95121 
1/*
2 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3 * Copyright (C) 1995, 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 *	$NetBSD: clock.c,v 1.9 2000/01/19 02:52:19 msaitoh Exp $
32 */
33/*
34 * Copyright (C) 2001 Benno Rice.
35 * All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 *    notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 *    notice, this list of conditions and the following disclaimer in the
44 *    documentation and/or other materials provided with the distribution.
45 *
46 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
47 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
48 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
49 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
52 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
53 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
54 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
55 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57
58#ifndef lint
59static const char rcsid[] =
60  "$FreeBSD: head/sys/powerpc/aim/clock.c 95121 2002-04-20 10:06:22Z benno $";
61#endif /* not lint */
62
63#include <sys/param.h>
64#include <sys/systm.h>
65#include <sys/kernel.h>
66#include <sys/sysctl.h>
67#include <sys/bus.h>
68#include <sys/timetc.h>
69#include <sys/interrupt.h>
70
71#include <dev/ofw/openfirm.h>
72
73#include <machine/clock.h>
74#include <machine/cpu.h>
75#include <machine/intr.h>
76
77#if 0 /* XXX */
78#include "adb.h"
79#else
80#define	NADB	0
81#endif
82
83/*
84 * Initially we assume a processor with a bus frequency of 12.5 MHz.
85 */
86static u_long ticks_per_sec = 12500000;
87static u_long		ns_per_tick = 80;
88static long		ticks_per_intr;
89static volatile u_long	lasttb;
90
91#define	SECDAY		86400
92#define	DIFF19041970	2082844800
93
94#if NADB > 0
95extern int adb_read_date_time(int *);
96extern int adb_set_date_time(int);
97#endif
98
99static int		clockinitted = 0;
100
101static timecounter_get_t	powerpc_get_timecount;
102
103static struct timecounter	powerpc_timecounter = {
104	powerpc_get_timecount,	/* get_timecount */
105	0,			/* no poll_pps */
106	~0u,			/* counter_mask */
107	0,			/* frequency */
108	"powerpc"		/* name */
109};
110
111SYSCTL_OPAQUE(_debug, OID_AUTO, powerpc_timecounter, CTLFLAG_RD,
112	&powerpc_timecounter, sizeof(powerpc_timecounter), "S,timecounter", "");
113
114void
115inittodr(time_t base)
116{
117	time_t		deltat;
118	u_int		rtc_time;
119	struct timespec	ts;
120
121	/*
122	 * If we can't read from RTC, use the fs time.
123	 */
124#if NADB > 0
125	if (adb_read_date_time(&rtc_time) < 0)
126#endif
127	{
128		ts.tv_sec = base;
129		ts.tv_nsec = 0;
130		tc_setclock(&ts);
131		return;
132	}
133	clockinitted = 1;
134	ts.tv_sec = rtc_time - DIFF19041970;
135
136	deltat = ts.tv_sec - base;
137	if (deltat < 0) {
138		deltat = -deltat;
139	}
140	if (deltat < 2 * SECDAY) {
141		tc_setclock(&ts);
142		return;
143	}
144
145	printf("WARNING: clock %s %d days",
146	    ts.tv_sec < base ? "lost" : "gained", (int)(deltat / SECDAY));
147
148	printf(" -- CHECK AND RESET THE DATE!\n");
149}
150
151/*
152 * Similar to the above
153 */
154void
155resettodr()
156{
157#if NADB > 0
158	u_int	rtc_time;
159
160	if (clockinitted) {
161		rtc_time = time.tv_sec + DIFF19041970;
162		adb_set_date_time(rtc_time);
163	}
164#endif
165}
166
167void
168decr_intr(struct clockframe *frame)
169{
170	u_long		tb;
171	long		tick;
172	int		nticks;
173	register_t	msr;
174
175	/*
176	 * Check whether we are initialized.
177	 */
178	if (!ticks_per_intr)
179		return;
180
181	/*
182	 * Based on the actual time delay since the last decrementer reload,
183	 * we arrange for earlier interrupt next time.
184	 */
185	__asm ("mftb %0; mfdec %1" : "=r"(tb), "=r"(tick));
186	for (nticks = 0; tick < 0; nticks++)
187		tick += ticks_per_intr;
188	mtdec(tick);
189	/*
190	 * lasttb is used during microtime. Set it to the virtual
191	 * start of this tick interval.
192	 */
193	lasttb = tb + tick - ticks_per_intr;
194
195	/*
196	 * This probably needs some kind of locking.
197	 */
198
199	intrcnt[CNT_CLOCK]++;
200
201	nticks += tickspending;
202	tickspending = 0;
203
204	/*
205	 * Reenable interrupts
206	 */
207	msr = mfmsr();
208	mtmsr(msr | PSL_EE | PSL_RI);
209
210	/*
211	 * Do standard timer interrupt stuff.
212	 * Do softclock stuff only on the last iteration.
213	 */
214	while (--nticks > 0) {
215		hardclock(frame);
216	}
217	hardclock(frame);
218}
219
220void
221cpu_initclocks(void)
222{
223	int qhandle, phandle;
224	char name[32];
225	unsigned int msr;
226
227	phandle = 0;
228
229	/*
230	 * Get this info during autoconf?				XXX
231	 */
232	for (qhandle = OF_peer(0); qhandle; qhandle = phandle) {
233		if (OF_getprop(qhandle, "device_type", name, sizeof name) >= 0
234		    && !strcmp(name, "cpu")
235		    && OF_getprop(qhandle, "timebase-frequency",
236				  &ticks_per_sec, sizeof ticks_per_sec) >= 0) {
237			/*
238			 * Should check for correct CPU here?		XXX
239			 */
240			msr = mfmsr();
241			mtmsr(msr & ~(PSL_EE|PSL_RI));
242
243			powerpc_timecounter.tc_frequency = ticks_per_sec;
244			tc_init(&powerpc_timecounter);
245
246			ns_per_tick = 1000000000 / ticks_per_sec;
247			ticks_per_intr = ticks_per_sec / hz;
248			__asm __volatile ("mftb %0" : "=r"(lasttb));
249			mtdec(ticks_per_intr);
250
251			mtmsr(msr);
252
253			break;
254		}
255		if ((phandle = OF_child(qhandle)))
256			continue;
257		while (qhandle) {
258			if ((phandle = OF_peer(qhandle)))
259				break;
260			qhandle = OF_parent(qhandle);
261		}
262	}
263	if (!phandle)
264		panic("no cpu node");
265}
266
267static __inline u_quad_t
268mftb(void)
269{
270	u_long		scratch;
271	u_quad_t	tb;
272
273	__asm ("1: mftbu %0; mftb %0+1; mftbu %1; cmpw 0,%0,%1; bne 1b"
274	      : "=r"(tb), "=r"(scratch));
275	return tb;
276}
277
278static unsigned
279powerpc_get_timecount(struct timecounter *tc)
280{
281	return mftb();
282}
283
284/*
285 * Wait for about n microseconds (at least!).
286 */
287void
288delay(int n)
289{
290	u_quad_t	tb;
291	u_long		tbh, tbl, scratch;
292
293	tb = mftb();
294	tb += (n * 1000 + ns_per_tick - 1) / ns_per_tick;
295	tbh = tb >> 32;
296	tbl = tb;
297	__asm ("1: mftbu %0; cmplw %0,%1; blt 1b; bgt 2f;"
298	       "mftb %0; cmplw %0,%2; blt 1b; 2:"
299	       : "=r"(scratch) : "r"(tbh), "r"(tbl));
300}
301
302/*
303 * Nothing to do.
304 */
305void
306setstatclockrate(int arg)
307{
308
309	/* Do nothing */
310}
311