2 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3 * Copyright (C) 1995, 1996 TooLs GmbH.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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.
31 * $NetBSD: clock.c,v 1.9 2000/01/19 02:52:19 msaitoh Exp $
34 * Copyright (C) 2001 Benno Rice.
35 * All rights reserved.
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
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.
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.
58 #include <sys/cdefs.h>
59 __FBSDID("$FreeBSD$");
61 #include <sys/param.h>
62 #include <sys/systm.h>
63 #include <sys/kernel.h>
64 #include <sys/sysctl.h>
66 #include <sys/interrupt.h>
69 #include <sys/timeet.h>
70 #include <sys/timetc.h>
72 #include <machine/clock.h>
73 #include <machine/intr_machdep.h>
74 #include <machine/platform.h>
75 #include <machine/psl.h>
76 #include <machine/spr.h>
77 #include <machine/cpu.h>
78 #include <machine/md_var.h>
81 * Initially we assume a processor with a bus frequency of 12.5 MHz.
83 static int initialized = 0;
84 static u_long ns_per_tick = 80;
85 static u_long ticks_per_sec = 12500000;
86 static u_long *decr_counts[MAXCPU];
88 #define DIFF19041970 2082844800
90 static int decr_et_start(struct eventtimer *et,
91 sbintime_t first, sbintime_t period);
92 static int decr_et_stop(struct eventtimer *et);
93 static timecounter_get_t decr_get_timecount;
96 int mode; /* 0 - off, 1 - periodic, 2 - one-shot. */
97 int32_t div; /* Periodic divisor. */
99 static DPCPU_DEFINE(struct decr_state, decr_state);
101 static struct eventtimer decr_et;
102 static struct timecounter decr_timecounter = {
103 decr_get_timecount, /* get_timecount */
105 ~0u, /* counter_mask */
107 "timebase" /* name */
111 * Decrementer interrupt handler.
114 decr_intr(struct trapframe *frame)
116 struct decr_state *s = DPCPU_PTR(decr_state);
121 (*decr_counts[curcpu])++;
124 * Interrupt handler must reset DIS to avoid getting another
125 * interrupt once EE is enabled.
127 mtspr(SPR_TSR, TSR_DIS);
129 CTR1(KTR_INTR, "%s: DEC interrupt", __func__);
134 if (decr_et.et_active)
135 decr_et.et_event_cb(&decr_et, decr_et.et_arg);
143 cpu_initclocks_bsp();
147 * BSP early initialization.
155 if (platform_smp_get_bsp(&cpu) != 0)
156 platform_smp_first_cpu(&cpu);
157 ticks_per_sec = platform_timebase_freq(&cpu);
158 ns_per_tick = 1000000000 / ticks_per_sec;
160 set_cputicker(mftb, ticks_per_sec, 0);
161 snprintf(buf, sizeof(buf), "cpu%d:decrementer", curcpu);
162 intrcnt_add(buf, &decr_counts[curcpu]);
169 * AP early initialization.
176 snprintf(buf, sizeof(buf), "cpu%d:decrementer", curcpu);
177 intrcnt_add(buf, &decr_counts[curcpu]);
183 * Final initialization.
189 decr_timecounter.tc_frequency = ticks_per_sec;
190 tc_init(&decr_timecounter);
191 decr_et.et_name = "decrementer";
192 decr_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT |
194 decr_et.et_quality = 1000;
195 decr_et.et_frequency = ticks_per_sec;
196 decr_et.et_min_period = (0x00000002LLU << 32) / ticks_per_sec;
197 decr_et.et_max_period = (0xfffffffeLLU << 32) / ticks_per_sec;
198 decr_et.et_start = decr_et_start;
199 decr_et.et_stop = decr_et_stop;
200 decr_et.et_priv = NULL;
201 et_register(&decr_et);
205 * Event timer start method.
208 decr_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
210 struct decr_state *s = DPCPU_PTR(decr_state);
215 s->div = (decr_et.et_frequency * period) >> 32;
221 fdiv = (decr_et.et_frequency * first) >> 32;
225 tcr = mfspr(SPR_TCR);
228 mtspr(SPR_DECAR, s->div);
238 * Event timer stop method.
241 decr_et_stop(struct eventtimer *et)
243 struct decr_state *s = DPCPU_PTR(decr_state);
248 tcr = mfspr(SPR_TCR);
249 tcr &= ~(TCR_DIE | TCR_ARE);
255 * Timecounter get method.
258 decr_get_timecount(struct timecounter *tc)
267 * Wait for about n microseconds (at least!).
272 u_quad_t start, end, now;
275 end = start + (u_quad_t)ticks_per_sec / (1000000ULL / n);
278 } while (now < end || (now > start && end < start));