1 /* $NetBSD: clock.c,v 1.2 2024/01/08 05:11:32 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Copyright (c) 1992, 1993
34 * The Regents of the University of California. All rights reserved.
35 *
36 * This software was developed by the Computer Systems Engineering group
37 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
38 * contributed to Berkeley.
39 *
40 * All advertising materials mentioning features or use of this software
41 * must display the following acknowledgement:
42 * This product includes software developed by the University of
43 * California, Lawrence Berkeley Laboratory.
44 *
45 * Redistribution and use in source and binary forms, with or without
46 * modification, are permitted provided that the following conditions
47 * are met:
48 * 1. Redistributions of source code must retain the above copyright
49 * notice, this list of conditions and the following disclaimer.
50 * 2. Redistributions in binary form must reproduce the above copyright
51 * notice, this list of conditions and the following disclaimer in the
52 * documentation and/or other materials provided with the distribution.
53 * 3. Neither the name of the University nor the names of its contributors
54 * may be used to endorse or promote products derived from this software
55 * without specific prior written permission.
56 *
57 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67 * SUCH DAMAGE.
68 *
69 * @(#)clock.c 8.1 (Berkeley) 6/11/93
70 */
71
72 #include <sys/cdefs.h>
73 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.2 2024/01/08 05:11:32 thorpej Exp $");
74
75 #include <sys/param.h>
76 #include <sys/kernel.h>
77 #include <sys/systm.h>
78 #include <sys/device.h>
79
80 #include <machine/clockvar.h>
81 #include <machine/psl.h>
82 #include <machine/bus.h>
83
84 static struct clock_vars {
85 struct clock_attach_args *args;
86 struct evcnt counter;
87 } virt68k_clocks[NCLOCKS];
88
89 static struct clock_handlers {
90 const char *name;
91 void (*func)(struct clockframe *);
92 } virt68k_clock_handlers[] = {
93 [CLOCK_HARDCLOCK] = { .name = "hardclock",
94 .func = hardclock },
95 [CLOCK_STATCLOCK] = { .name = "statclock",
96 .func = statclock },
97 };
98
99 void *clock_devices[NCLOCKS];
100
101 /*
102 * Statistics clock interval and variance, in usec. Variance must be a
103 * power of two. Since this gives us an even number, not an odd number,
104 * we discard one case and compensate. That is, a variance of 1024 would
105 * give us offsets in [0..1023]. Instead, we take offsets in [1..1023].
106 * This is symmetric about the point 512, or statvar/2, and thus averages
107 * to that value (assuming uniform random numbers).
108 */
109 /* XXX fix comment to match value */
110 int clock_statvar = 8192;
111 int clock_statmin; /* statclock interval - (1/2 * variance) */
112
113 static void (*clock_delay_func)(device_t, unsigned int);
114 static device_t clock_delay_dev;
115
116 /*
117 * Common parts of clock autoconfiguration.
118 */
119 void
clock_attach(device_t dev,struct clock_attach_args * ca,void (* delay_func)(device_t,unsigned int))120 clock_attach(device_t dev, struct clock_attach_args *ca,
121 void (*delay_func)(device_t, unsigned int))
122 {
123 /* Hook up that which we need. */
124 KASSERT(ca->ca_which >= 0);
125 KASSERT(ca->ca_which < NCLOCKS);
126
127 KASSERT(clock_devices[ca->ca_which] == NULL);
128 KASSERT(virt68k_clocks[ca->ca_which].args == NULL);
129
130 clock_devices[ca->ca_which] = ca->ca_arg;
131 virt68k_clocks[ca->ca_which].args = ca;
132
133 evcnt_attach_dynamic(&virt68k_clocks[ca->ca_which].counter,
134 EVCNT_TYPE_INTR, ca->ca_parent_evcnt,
135 device_xname(dev), virt68k_clock_handlers[ca->ca_which].name);
136
137 if (delay_func != NULL && clock_delay_dev == NULL) {
138 aprint_normal_dev(dev, "Using as delay() timer.\n");
139 clock_delay_func = delay_func;
140 clock_delay_dev = dev;
141 }
142 }
143
144 void
delay(unsigned int usec)145 delay(unsigned int usec)
146 {
147 if (clock_delay_func != NULL) {
148 (*clock_delay_func)(clock_delay_dev, usec);
149 }
150 }
151
152 const char *
clock_name(int which)153 clock_name(int which)
154 {
155 KASSERT(which >= 0);
156 KASSERT(which < NCLOCKS);
157
158 return virt68k_clock_handlers[which].name;
159 }
160
161 /*
162 * Set up the real-time and statistics clocks. Leave stathz 0 only
163 * if no alternative timer is available.
164 *
165 * The frequencies of these clocks must be an even number of microseconds.
166 */
167 void
cpu_initclocks(void)168 cpu_initclocks(void)
169 {
170 int i, statint = 0, minint = 0;
171
172 if (virt68k_clocks[CLOCK_HARDCLOCK].args == NULL) {
173 panic("Clock not configured");
174 }
175
176 if (1000000 % hz) {
177 aprint_error("Cannot get %d Hz clock; using 100 Hz\n", hz);
178 hz = 100;
179 tick = 1000000 / hz;
180 }
181
182 if (virt68k_clocks[CLOCK_STATCLOCK].args == NULL) {
183 aprint_normal("No statclock; using hardclock.\n");
184 stathz = 0;
185 statint = 0;
186 } else if (stathz == 0) {
187 stathz = hz;
188 if (1000000 % stathz) {
189 aprint_error("Cannot get %d Hz statclock; "
190 "using 100 Hz\n", stathz);
191 stathz = 100;
192 }
193 profhz = stathz; /* always */
194 statint = 1000000 / stathz;
195 minint = statint / 2 + 100;
196 while (clock_statvar > minint)
197 clock_statvar >>= 1;
198 clock_statmin = statint - (clock_statvar >> 1);
199 }
200
201 for (i = 0; i < NCLOCKS; i++) {
202 struct clock_attach_args *ca = virt68k_clocks[i].args;
203 unsigned int freq, interval;
204
205 if (ca == NULL) {
206 continue;
207 }
208 switch (i) {
209 case CLOCK_HARDCLOCK:
210 freq = hz;
211 interval = tick;
212 break;
213
214 case CLOCK_STATCLOCK:
215 freq = stathz;
216 interval = statint;
217 break;
218
219 default:
220 KASSERT(0);
221 }
222
223 aprint_normal("Initialzing %s: freq=%u Hz, interval=%u usec\n",
224 clock_name(i), freq, interval);
225 ca->ca_initfunc(ca->ca_arg, interval,
226 &virt68k_clocks[i].counter,
227 virt68k_clock_handlers[i].func);
228 }
229 }
230
231 void
setstatclockrate(int newhz)232 setstatclockrate(int newhz)
233 {
234
235 /* XXX should we do something here? XXX */
236 }
237