2 * Copyright (c) 2005 Poul-Henning Kamp
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
37 #include <sys/timetc.h>
39 #include <contrib/dev/acpica/acpi.h>
40 #include <dev/acpica/acpivar.h>
42 ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
44 /* ACPI CA debugging */
45 #define _COMPONENT ACPI_TIMER
46 ACPI_MODULE_NAME("HPET")
48 struct acpi_hpet_softc {
50 struct resource *mem_res;
54 static u_int hpet_get_timecount(struct timecounter *tc);
55 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
57 static char *hpet_ids[] = { "PNP0103", NULL };
59 #define HPET_MEM_WIDTH 0x400 /* Expected memory region size */
60 #define HPET_OFFSET_INFO 0 /* Location of info in region */
61 #define HPET_OFFSET_PERIOD 4 /* Location of period (1/hz) */
62 #define HPET_OFFSET_ENABLE 0x10 /* Location of enable word */
63 #define HPET_OFFSET_VALUE 0xf0 /* Location of actual timer value */
65 struct timecounter hpet_timecounter = {
66 .tc_get_timecount = hpet_get_timecount,
67 .tc_counter_mask = ~0u,
73 hpet_get_timecount(struct timecounter *tc)
75 struct acpi_hpet_softc *sc;
78 return (bus_read_4(sc->mem_res, HPET_OFFSET_VALUE));
82 acpi_hpet_probe(device_t dev)
84 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
86 if (acpi_disabled("hpet") ||
87 ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
88 device_get_unit(dev) != 0)
91 device_set_desc(dev, "High Precision Event Timer");
96 acpi_hpet_attach(device_t dev)
98 struct acpi_hpet_softc *sc;
103 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
105 sc = device_get_softc(dev);
107 sc->handle = acpi_get_handle(dev);
110 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
112 if (sc->mem_res == NULL)
115 /* Validate that we can access the whole region. */
116 if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
117 device_printf(dev, "memory region width %ld too small\n",
118 rman_get_size(sc->mem_res));
119 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
123 /* Read basic statistics about the timer. */
124 val = bus_read_4(sc->mem_res, HPET_OFFSET_PERIOD);
125 freq = (1000000000000000LL + val / 2) / val;
127 val = bus_read_4(sc->mem_res, HPET_OFFSET_INFO);
129 "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
130 val >> 16, val & 0xff, (val >> 18) & 0xf, freq,
131 ((val >> 15) & 1) ? " leg_route" : "",
132 ((val >> 13) & 1) ? " count_size" : "");
135 /* Be sure it is enabled. */
136 bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
138 if (testenv("debug.acpi.hpet_test"))
141 hpet_timecounter.tc_frequency = freq;
142 hpet_timecounter.tc_priv = sc;
143 tc_init(&hpet_timecounter);
149 acpi_hpet_detach(device_t dev)
151 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
153 /* XXX Without a tc_remove() function, we can't detach. */
158 acpi_hpet_resume(device_t dev)
160 struct acpi_hpet_softc *sc;
162 /* Re-enable the timer after a resume to keep the clock advancing. */
163 sc = device_get_softc(dev);
164 bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
169 /* Print some basic latency/rate information to assist in debugging. */
171 acpi_hpet_test(struct acpi_hpet_softc *sc)
175 struct bintime b0, b1, b2;
181 u1 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
182 for (i = 1; i < 1000; i++)
183 u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
185 u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
187 bintime_sub(&b2, &b1);
188 bintime_sub(&b1, &b0);
189 bintime_sub(&b2, &b1);
190 bintime2timespec(&b2, &ts);
192 device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
193 (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
195 device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
198 static device_method_t acpi_hpet_methods[] = {
199 /* Device interface */
200 DEVMETHOD(device_probe, acpi_hpet_probe),
201 DEVMETHOD(device_attach, acpi_hpet_attach),
202 DEVMETHOD(device_detach, acpi_hpet_detach),
203 DEVMETHOD(device_resume, acpi_hpet_resume),
208 static driver_t acpi_hpet_driver = {
211 sizeof(struct acpi_hpet_softc),
214 static devclass_t acpi_hpet_devclass;
216 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
217 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);