acpi_timer.c revision 1.16 1 1.16 jruoho /* $NetBSD: acpi_timer.c,v 1.16 2010/03/05 17:04:26 jruoho Exp $ */
2 1.16 jruoho
3 1.16 jruoho /*-
4 1.16 jruoho * Copyright (c) 2006 Matthias Drochner <drochner (at) NetBSD.org>
5 1.16 jruoho * All rights reserved.
6 1.16 jruoho *
7 1.16 jruoho * Redistribution and use in source and binary forms, with or without
8 1.16 jruoho * modification, are permitted provided that the following conditions
9 1.16 jruoho * are met:
10 1.16 jruoho * 1. Redistributions of source code must retain the above copyright
11 1.16 jruoho * notice, this list of conditions and the following disclaimer.
12 1.16 jruoho * 2. Redistributions in binary form must reproduce the above copyright
13 1.16 jruoho * notice, this list of conditions and the following disclaimer in the
14 1.16 jruoho * documentation and/or other materials provided with the distribution.
15 1.16 jruoho *
16 1.16 jruoho * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 1.16 jruoho * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 1.16 jruoho * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 1.16 jruoho * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 1.16 jruoho * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 1.16 jruoho * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 1.16 jruoho * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 1.16 jruoho * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 1.16 jruoho * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 1.16 jruoho * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 1.16 jruoho * POSSIBILITY OF SUCH DAMAGE.
27 1.16 jruoho */
28 1.4 xtraeme
29 1.4 xtraeme #include <sys/cdefs.h>
30 1.16 jruoho __KERNEL_RCSID(0, "$NetBSD: acpi_timer.c,v 1.16 2010/03/05 17:04:26 jruoho Exp $");
31 1.1 drochner
32 1.1 drochner #include <sys/types.h>
33 1.1 drochner #include <sys/systm.h>
34 1.1 drochner #include <sys/time.h>
35 1.1 drochner #include <sys/timetc.h>
36 1.15 jruoho
37 1.15 jruoho #include <dev/acpi/acpivar.h>
38 1.10 joerg #include <dev/acpi/acpi_timer.h>
39 1.15 jruoho
40 1.12 jmcneill #include <machine/acpi_machdep.h>
41 1.1 drochner
42 1.2 drochner static int acpitimer_test(void);
43 1.2 drochner static uint32_t acpitimer_delta(uint32_t, uint32_t);
44 1.2 drochner static u_int acpitimer_read_safe(struct timecounter *);
45 1.2 drochner static u_int acpitimer_read_fast(struct timecounter *);
46 1.1 drochner
47 1.1 drochner static struct timecounter acpi_timecounter = {
48 1.2 drochner acpitimer_read_safe,
49 1.1 drochner 0,
50 1.1 drochner 0x00ffffff,
51 1.1 drochner PM_TIMER_FREQUENCY,
52 1.2 drochner "ACPI-Safe",
53 1.6 christos 900,
54 1.6 christos NULL,
55 1.6 christos NULL,
56 1.1 drochner };
57 1.1 drochner
58 1.1 drochner int
59 1.13 cegger acpitimer_init(void)
60 1.1 drochner {
61 1.1 drochner uint32_t bits;
62 1.2 drochner int i, j;
63 1.1 drochner ACPI_STATUS res;
64 1.1 drochner
65 1.1 drochner res = AcpiGetTimerResolution(&bits);
66 1.1 drochner if (res != AE_OK)
67 1.1 drochner return (-1);
68 1.1 drochner
69 1.1 drochner if (bits == 32)
70 1.1 drochner acpi_timecounter.tc_counter_mask = 0xffffffff;
71 1.2 drochner
72 1.2 drochner j = 0;
73 1.2 drochner for (i = 0; i < 10; i++)
74 1.2 drochner j += acpitimer_test();
75 1.3 xtraeme
76 1.2 drochner if (j >= 10) {
77 1.2 drochner acpi_timecounter.tc_name = "ACPI-Fast";
78 1.2 drochner acpi_timecounter.tc_get_timecount = acpitimer_read_fast;
79 1.2 drochner acpi_timecounter.tc_quality = 1000;
80 1.2 drochner }
81 1.2 drochner
82 1.1 drochner tc_init(&acpi_timecounter);
83 1.11 ad aprint_verbose("%s %d-bit timer\n", acpi_timecounter.tc_name, bits);
84 1.1 drochner
85 1.2 drochner return (0);
86 1.2 drochner }
87 1.1 drochner
88 1.14 dyoung int
89 1.14 dyoung acpitimer_detach(void)
90 1.14 dyoung {
91 1.14 dyoung return tc_detach(&acpi_timecounter);
92 1.14 dyoung }
93 1.14 dyoung
94 1.2 drochner static u_int
95 1.8 christos acpitimer_read_fast(struct timecounter *tc)
96 1.2 drochner {
97 1.2 drochner uint32_t t;
98 1.2 drochner
99 1.2 drochner AcpiGetTimer(&t);
100 1.2 drochner return (t);
101 1.1 drochner }
102 1.1 drochner
103 1.1 drochner /*
104 1.1 drochner * Some chipsets (PIIX4 variants) do not latch correctly; there
105 1.1 drochner * is a chance that a transition is hit.
106 1.1 drochner */
107 1.1 drochner static u_int
108 1.8 christos acpitimer_read_safe(struct timecounter *tc)
109 1.1 drochner {
110 1.1 drochner uint32_t t1, t2, t3;
111 1.1 drochner
112 1.1 drochner AcpiGetTimer(&t2);
113 1.1 drochner AcpiGetTimer(&t3);
114 1.1 drochner do {
115 1.1 drochner t1 = t2;
116 1.1 drochner t2 = t3;
117 1.1 drochner AcpiGetTimer(&t3);
118 1.1 drochner } while ((t1 > t2) || (t2 > t3));
119 1.1 drochner return (t2);
120 1.1 drochner }
121 1.1 drochner
122 1.2 drochner static uint32_t
123 1.2 drochner acpitimer_delta(uint32_t end, uint32_t start)
124 1.2 drochner {
125 1.2 drochner uint32_t delta;
126 1.2 drochner u_int mask = acpi_timecounter.tc_counter_mask;
127 1.2 drochner
128 1.2 drochner if (end >= start)
129 1.2 drochner delta = end - start;
130 1.2 drochner else
131 1.2 drochner delta = ((mask - start) + end + 1) & mask;
132 1.2 drochner
133 1.2 drochner return (delta);
134 1.2 drochner }
135 1.2 drochner
136 1.2 drochner #define N 2000
137 1.2 drochner static int
138 1.13 cegger acpitimer_test(void)
139 1.2 drochner {
140 1.2 drochner uint32_t last, this, delta;
141 1.2 drochner int minl, maxl, n;
142 1.2 drochner
143 1.2 drochner minl = 10000000;
144 1.2 drochner maxl = 0;
145 1.2 drochner
146 1.12 jmcneill acpi_md_OsDisableInterrupt();
147 1.2 drochner AcpiGetTimer(&last);
148 1.2 drochner for (n = 0; n < N; n++) {
149 1.2 drochner AcpiGetTimer(&this);
150 1.2 drochner delta = acpitimer_delta(this, last);
151 1.2 drochner if (delta > maxl)
152 1.2 drochner maxl = delta;
153 1.2 drochner else if (delta < minl)
154 1.2 drochner minl = delta;
155 1.2 drochner last = this;
156 1.2 drochner }
157 1.12 jmcneill acpi_md_OsEnableInterrupt();
158 1.2 drochner
159 1.2 drochner if (maxl - minl > 2 )
160 1.2 drochner n = 0;
161 1.2 drochner else if (minl < 0 || maxl == 0)
162 1.2 drochner n = 0;
163 1.2 drochner else
164 1.2 drochner n = 1;
165 1.2 drochner
166 1.2 drochner return (n);
167 1.2 drochner }
168