clock.c revision 113038 
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#include <sys/cdefs.h>
59__FBSDID("$FreeBSD: head/sys/powerpc/aim/clock.c 113038 2003-04-03 21:36:33Z obrien $");
60
61#include <sys/param.h>
62#include <sys/systm.h>
63#include <sys/kernel.h>
64#include <sys/sysctl.h>
65#include <sys/bus.h>
66#include <sys/timetc.h>
67#include <sys/interrupt.h>
68
69#include <dev/ofw/openfirm.h>
70
71#include <machine/clock.h>
72#include <machine/cpu.h>
73#include <machine/intr.h>
74
75#if 0 /* XXX */
76#include "adb.h"
77#else
78#define	NADB	0
79#endif
80
81/*
82 * Initially we assume a processor with a bus frequency of 12.5 MHz.
83 */
84u_int			tickspending;
85u_long			ns_per_tick = 80;
86static u_long		ticks_per_sec = 12500000;
87static long		ticks_per_intr;
88static volatile u_long	lasttb;
89
90#define	SECDAY		86400
91#define	DIFF19041970	2082844800
92
93#if NADB > 0
94extern int adb_read_date_time(int *);
95extern int adb_set_date_time(int);
96#endif
97
98static int		clockinitted = 0;
99
100static timecounter_get_t	decr_get_timecount;
101
102static struct timecounter	decr_timecounter = {
103	decr_get_timecount,	/* get_timecount */
104	0,			/* no poll_pps */
105	~0u,			/* counter_mask */
106	0,			/* frequency */
107	"decrementer"		/* name */
108};
109
110void
111inittodr(time_t base)
112{
113	time_t		deltat;
114	u_int		rtc_time;
115	struct timespec	ts;
116	phandle_t	phandle;
117	ihandle_t	ihandle;
118	char		rtcpath[128];
119	u_int		rtcsecs;
120
121	/*
122	 * If we can't read from RTC, use the fs time.
123	 */
124	phandle = OF_finddevice("rtc");
125	if (phandle != -1) {
126		OF_package_to_path(phandle, rtcpath, sizeof(rtcpath));
127		ihandle = OF_open(rtcpath);
128		if (ihandle != -1) {
129			if (OF_call_method("read-rtc", ihandle,
130			    0, 1, &rtcsecs))
131				printf("RTC call method error\n");
132			else {
133				ts.tv_sec = rtcsecs - DIFF19041970;
134				ts.tv_nsec = 0;
135				tc_setclock(&ts);
136				return;
137			}
138		}
139	}
140
141#if NADB > 0
142	if (adb_read_date_time(&rtc_time) < 0)
143#endif
144	{
145		ts.tv_sec = base;
146		ts.tv_nsec = 0;
147		tc_setclock(&ts);
148		return;
149	}
150	clockinitted = 1;
151	ts.tv_sec = rtc_time - DIFF19041970;
152
153	deltat = ts.tv_sec - base;
154	if (deltat < 0) {
155		deltat = -deltat;
156	}
157	if (deltat < 2 * SECDAY) {
158		tc_setclock(&ts);
159		return;
160	}
161
162	printf("WARNING: clock %s %d days",
163	    ts.tv_sec < base ? "lost" : "gained", (int)(deltat / SECDAY));
164
165	printf(" -- CHECK AND RESET THE DATE!\n");
166}
167
168/*
169 * Similar to the above
170 */
171void
172resettodr()
173{
174#if NADB > 0
175	u_int	rtc_time;
176
177	if (clockinitted) {
178		rtc_time = time.tv_sec + DIFF19041970;
179		adb_set_date_time(rtc_time);
180	}
181#endif
182}
183
184void
185decr_intr(struct clockframe *frame)
186{
187	u_long		tb;
188	long		tick;
189	int		nticks;
190	register_t	msr;
191
192	/*
193	 * Check whether we are initialized.
194	 */
195	if (!ticks_per_intr)
196		return;
197
198	/*
199	 * Based on the actual time delay since the last decrementer reload,
200	 * we arrange for earlier interrupt next time.
201	 */
202	__asm ("mftb %0; mfdec %1" : "=r"(tb), "=r"(tick));
203	for (nticks = 0; tick < 0; nticks++)
204		tick += ticks_per_intr;
205	mtdec(tick);
206	/*
207	 * lasttb is used during microtime. Set it to the virtual
208	 * start of this tick interval.
209	 */
210	lasttb = tb + tick - ticks_per_intr;
211
212	nticks += tickspending;
213	tickspending = 0;
214
215	/*
216	 * Reenable interrupts
217	 */
218#if 0
219	msr = mfmsr();
220	mtmsr(msr | PSL_EE | PSL_RI);
221#endif
222	/*
223	 * Do standard timer interrupt stuff.
224	 * Do softclock stuff only on the last iteration.
225	 */
226#if 0
227	while (--nticks > 0) {
228		hardclock(frame);
229	}
230#endif
231	hardclock(frame);
232}
233
234void
235cpu_initclocks(void)
236{
237
238	return;
239}
240
241void
242decr_init(void)
243{
244	int qhandle, phandle;
245	char name[32];
246	unsigned int msr;
247
248	phandle = 0;
249
250	/*
251	 * Get this info during autoconf?				XXX
252	 */
253	for (qhandle = OF_peer(0); qhandle; qhandle = phandle) {
254		if (OF_getprop(qhandle, "device_type", name, sizeof name) >= 0
255		    && !strcmp(name, "cpu")
256		    && OF_getprop(qhandle, "timebase-frequency",
257				  &ticks_per_sec, sizeof ticks_per_sec) >= 0) {
258			/*
259			 * Should check for correct CPU here?		XXX
260			 */
261			msr = mfmsr();
262			mtmsr(msr & ~(PSL_EE|PSL_RI));
263
264			decr_timecounter.tc_frequency = ticks_per_sec;
265			tc_init(&decr_timecounter);
266
267			ns_per_tick = 1000000000 / ticks_per_sec;
268			ticks_per_intr = ticks_per_sec / hz;
269			__asm __volatile ("mftb %0" : "=r"(lasttb));
270			mtdec(ticks_per_intr);
271
272			mtmsr(msr);
273
274			break;
275		}
276		if ((phandle = OF_child(qhandle)))
277			continue;
278		while (qhandle) {
279			if ((phandle = OF_peer(qhandle)))
280				break;
281			qhandle = OF_parent(qhandle);
282		}
283	}
284	if (!phandle)
285		panic("no cpu node");
286}
287
288static __inline u_quad_t
289mftb(void)
290{
291	u_long		scratch;
292	u_quad_t	tb;
293
294	__asm ("1: mftbu %0; mftb %0+1; mftbu %1; cmpw 0,%0,%1; bne 1b"
295	      : "=r"(tb), "=r"(scratch));
296	return tb;
297}
298
299static unsigned
300decr_get_timecount(struct timecounter *tc)
301{
302	return mftb();
303}
304
305/*
306 * Wait for about n microseconds (at least!).
307 */
308void
309delay(int n)
310{
311	u_quad_t	tb, ttb;
312
313	tb = mftb();
314	ttb = tb + (n * 1000 + ns_per_tick - 1) / ns_per_tick;
315	while (tb < ttb)
316		tb = mftb();
317}
318
319/*
320 * Nothing to do.
321 */
322void
323cpu_startprofclock(void)
324{
325
326	/* Do nothing */
327}
328
329void
330cpu_stopprofclock(void)
331{
332}
333