1/* $NetBSD: hpet.c,v 1.13 2011/10/31 12:47:15 yamt Exp $ */
2
3/*
4 * Copyright (c) 2006 Nicolas Joly
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31/*
32 * High Precision Event Timer.
33 */
34
35#include <sys/cdefs.h>
36__KERNEL_RCSID(0, "$NetBSD: hpet.c,v 1.13 2011/10/31 12:47:15 yamt Exp $");
37
38#include <sys/systm.h>
39#include <sys/device.h>
40#include <sys/module.h>
41
42#include <sys/time.h>
43#include <sys/timetc.h>
44
45#include <sys/bus.h>
46
47#include <dev/ic/hpetreg.h>
48#include <dev/ic/hpetvar.h>
49
50static u_int hpet_get_timecount(struct timecounter *);
51static bool hpet_resume(device_t, const pmf_qual_t *);
52
53int
54hpet_detach(device_t dv, int flags)
55{
56 struct hpet_softc *sc = device_private(dv);
57 int rc;
58
59 if ((rc = tc_detach(&sc->sc_tc)) != 0)
60 return rc;
61
62 pmf_device_deregister(dv);
63
64 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, sc->sc_config);
65
66 return 0;
67}
68
69void
70hpet_attach_subr(device_t dv)
71{
72 struct hpet_softc *sc = device_private(dv);
73 struct timecounter *tc;
74 uint64_t tmp;
75 uint32_t val;
76 int i;
77
78 tc = &sc->sc_tc;
79
80 tc->tc_name = device_xname(dv);
81 tc->tc_get_timecount = hpet_get_timecount;
82 tc->tc_quality = 2000;
83
84 tc->tc_counter_mask = 0xffffffff;
85
86 /* Get frequency */
87 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_PERIOD);
88 if (val == 0 || val > HPET_PERIOD_MAX) {
89 aprint_error_dev(dv, "invalid timer period\n");
90 return;
91 }
92
93 /*
94 * The following loop is a workaround for AMD SB700 based systems.
95 * http://kerneltrap.org/mailarchive/git-commits-head/2008/8/17/2964724
96 * http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a6825f1c1fa83b1e92b6715ee5771a4d6524d3b9
97 */
98 for (i = 0; bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG)
99 == 0xffffffff; i++) {
100 if (i >= 1000) {
101 aprint_error_dev(dv,
102 "HPET_CONFIG value = 0xffffffff\n");
103 return;
104 }
105 }
106
107 tmp = (1000000000000000ULL * 2) / val;
108 tc->tc_frequency = (tmp / 2) + (tmp & 1);
109
110 /* Enable timer */
111 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG);
112 sc->sc_config = val;
113 if ((val & HPET_CONFIG_ENABLE) == 0) {
114 val |= HPET_CONFIG_ENABLE;
115 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, val);
116 }
117
118 tc->tc_priv = sc;
119 tc_init(tc);
120
121 if (!pmf_device_register(dv, NULL, hpet_resume))
122 aprint_error_dev(dv, "couldn't establish power handler\n");
123}
124
125static u_int
126hpet_get_timecount(struct timecounter *tc)
127{
128 struct hpet_softc *sc = tc->tc_priv;
129
130 return bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_MCOUNT_LO);
131}
132
133static bool
134hpet_resume(device_t dv, const pmf_qual_t *qual)
135{
136 struct hpet_softc *sc = device_private(dv);
137 uint32_t val;
138
139 val = bus_space_read_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG);
140 val |= HPET_CONFIG_ENABLE;
141 bus_space_write_4(sc->sc_memt, sc->sc_memh, HPET_CONFIG, val);
142
143 return true;
144}
145
146MODULE(MODULE_CLASS_DRIVER, hpet, NULL);
147
148#ifdef _MODULE
149#include "ioconf.c"
150#endif
151
152static int
153hpet_modcmd(modcmd_t cmd, void *aux)
154{
155 int rv = 0;
156
157 switch (cmd) {
158
159 case MODULE_CMD_INIT:
160
161#ifdef _MODULE
162 rv = config_init_component(cfdriver_ioconf_hpet,
163 cfattach_ioconf_hpet, cfdata_ioconf_hpet);
164#endif
165 break;
166
167 case MODULE_CMD_FINI:
168
169#ifdef _MODULE
170 rv = config_fini_component(cfdriver_ioconf_hpet,
171 cfattach_ioconf_hpet, cfdata_ioconf_hpet);
172#endif
173 break;
174
175 default:
176 rv = ENOTTY;
177 }
178
179 return rv;
180}
181