acpi_timer.c revision 1.19 1 1.19 jruoho /* $NetBSD: acpi_timer.c,v 1.19 2011/01/02 05:48:55 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 1.19 jruoho __KERNEL_RCSID(0, "$NetBSD: acpi_timer.c,v 1.19 2011/01/02 05:48:55 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 1.17 jruoho static int acpitimer_test(void);
43 1.1 drochner
44 1.1 drochner static struct timecounter acpi_timecounter = {
45 1.2 drochner acpitimer_read_safe,
46 1.1 drochner 0,
47 1.1 drochner 0x00ffffff,
48 1.1 drochner PM_TIMER_FREQUENCY,
49 1.2 drochner "ACPI-Safe",
50 1.6 christos 900,
51 1.6 christos NULL,
52 1.6 christos NULL,
53 1.1 drochner };
54 1.1 drochner
55 1.1 drochner int
56 1.17 jruoho acpitimer_init(struct acpi_softc *sc)
57 1.1 drochner {
58 1.19 jruoho const uint32_t flags = AcpiGbl_FADT.Flags;
59 1.19 jruoho ACPI_STATUS rv;
60 1.1 drochner uint32_t bits;
61 1.2 drochner int i, j;
62 1.1 drochner
63 1.19 jruoho rv = AcpiGetTimerResolution(&bits);
64 1.17 jruoho
65 1.19 jruoho if (ACPI_FAILURE(rv))
66 1.18 jruoho return -1;
67 1.1 drochner
68 1.1 drochner if (bits == 32)
69 1.1 drochner acpi_timecounter.tc_counter_mask = 0xffffffff;
70 1.2 drochner
71 1.17 jruoho for (i = j = 0; i < 10; i++)
72 1.2 drochner j += acpitimer_test();
73 1.3 xtraeme
74 1.2 drochner if (j >= 10) {
75 1.2 drochner acpi_timecounter.tc_name = "ACPI-Fast";
76 1.2 drochner acpi_timecounter.tc_get_timecount = acpitimer_read_fast;
77 1.2 drochner acpi_timecounter.tc_quality = 1000;
78 1.2 drochner }
79 1.17 jruoho
80 1.1 drochner tc_init(&acpi_timecounter);
81 1.1 drochner
82 1.19 jruoho aprint_debug_dev(sc->sc_dev, "%s %d-bit timer\n",
83 1.19 jruoho acpi_timecounter.tc_name, bits);
84 1.19 jruoho
85 1.19 jruoho if ((flags & ACPI_FADT_PLATFORM_CLOCK) != 0)
86 1.19 jruoho aprint_debug_dev(sc->sc_dev,
87 1.19 jruoho "warning: timer may be unreliable\n");
88 1.17 jruoho
89 1.17 jruoho return 0;
90 1.2 drochner }
91 1.1 drochner
92 1.14 dyoung int
93 1.14 dyoung acpitimer_detach(void)
94 1.14 dyoung {
95 1.17 jruoho
96 1.14 dyoung return tc_detach(&acpi_timecounter);
97 1.14 dyoung }
98 1.14 dyoung
99 1.17 jruoho u_int
100 1.8 christos acpitimer_read_fast(struct timecounter *tc)
101 1.2 drochner {
102 1.2 drochner uint32_t t;
103 1.2 drochner
104 1.17 jruoho (void)AcpiGetTimer(&t);
105 1.17 jruoho
106 1.17 jruoho return t;
107 1.1 drochner }
108 1.1 drochner
109 1.1 drochner /*
110 1.18 jruoho * Some chipsets (PIIX4 variants) do not latch correctly;
111 1.18 jruoho * there is a chance that a transition is hit.
112 1.1 drochner */
113 1.17 jruoho u_int
114 1.8 christos acpitimer_read_safe(struct timecounter *tc)
115 1.1 drochner {
116 1.1 drochner uint32_t t1, t2, t3;
117 1.1 drochner
118 1.17 jruoho (void)AcpiGetTimer(&t2);
119 1.17 jruoho (void)AcpiGetTimer(&t3);
120 1.17 jruoho
121 1.1 drochner do {
122 1.1 drochner t1 = t2;
123 1.1 drochner t2 = t3;
124 1.17 jruoho
125 1.17 jruoho (void)AcpiGetTimer(&t3);
126 1.17 jruoho
127 1.1 drochner } while ((t1 > t2) || (t2 > t3));
128 1.17 jruoho
129 1.17 jruoho return t2;
130 1.1 drochner }
131 1.1 drochner
132 1.18 jruoho uint32_t
133 1.2 drochner acpitimer_delta(uint32_t end, uint32_t start)
134 1.2 drochner {
135 1.17 jruoho const u_int mask = acpi_timecounter.tc_counter_mask;
136 1.2 drochner uint32_t delta;
137 1.2 drochner
138 1.2 drochner if (end >= start)
139 1.2 drochner delta = end - start;
140 1.2 drochner else
141 1.2 drochner delta = ((mask - start) + end + 1) & mask;
142 1.2 drochner
143 1.17 jruoho return delta;
144 1.2 drochner }
145 1.2 drochner
146 1.2 drochner #define N 2000
147 1.17 jruoho
148 1.2 drochner static int
149 1.13 cegger acpitimer_test(void)
150 1.2 drochner {
151 1.2 drochner uint32_t last, this, delta;
152 1.2 drochner int minl, maxl, n;
153 1.2 drochner
154 1.2 drochner minl = 10000000;
155 1.2 drochner maxl = 0;
156 1.2 drochner
157 1.12 jmcneill acpi_md_OsDisableInterrupt();
158 1.17 jruoho
159 1.17 jruoho (void)AcpiGetTimer(&last);
160 1.17 jruoho
161 1.2 drochner for (n = 0; n < N; n++) {
162 1.17 jruoho
163 1.17 jruoho (void)AcpiGetTimer(&this);
164 1.17 jruoho
165 1.2 drochner delta = acpitimer_delta(this, last);
166 1.17 jruoho
167 1.2 drochner if (delta > maxl)
168 1.2 drochner maxl = delta;
169 1.2 drochner else if (delta < minl)
170 1.2 drochner minl = delta;
171 1.17 jruoho
172 1.2 drochner last = this;
173 1.2 drochner }
174 1.17 jruoho
175 1.12 jmcneill acpi_md_OsEnableInterrupt();
176 1.2 drochner
177 1.2 drochner if (maxl - minl > 2 )
178 1.2 drochner n = 0;
179 1.2 drochner else if (minl < 0 || maxl == 0)
180 1.2 drochner n = 0;
181 1.2 drochner else
182 1.2 drochner n = 1;
183 1.2 drochner
184 1.17 jruoho return n;
185 1.2 drochner }
186