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 static devclass_t acpi_hpet_devclass;
46 /* ACPI CA debugging */
47 #define _COMPONENT ACPI_TIMER
48 ACPI_MODULE_NAME("HPET")
50 struct acpi_hpet_softc {
52 struct resource *mem_res;
56 static u_int hpet_get_timecount(struct timecounter *tc);
57 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
59 static char *hpet_ids[] = { "PNP0103", NULL };
61 #define HPET_MEM_WIDTH 0x400 /* Expected memory region size */
62 #define HPET_OFFSET_INFO 0 /* Location of info in region */
63 #define HPET_OFFSET_PERIOD 4 /* Location of period (1/hz) */
64 #define HPET_OFFSET_ENABLE 0x10 /* Location of enable word */
65 #define HPET_OFFSET_VALUE 0xf0 /* Location of actual timer value */
67 #define DEV_HPET(x) (acpi_get_magic(x) == (uintptr_t)&acpi_hpet_devclass)
69 struct timecounter hpet_timecounter = {
70 .tc_get_timecount = hpet_get_timecount,
71 .tc_counter_mask = ~0u,
77 hpet_get_timecount(struct timecounter *tc)
79 struct acpi_hpet_softc *sc;
82 return (bus_read_4(sc->mem_res, HPET_OFFSET_VALUE));
85 /* Discover the HPET via the ACPI table of the same name. */
87 acpi_hpet_table_probe(device_t parent)
89 ACPI_TABLE_HPET *hpet;
90 ACPI_TABLE_HEADER *hdr;
94 /* Currently, ID and minimum clock tick info is unused. */
96 status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
97 if (ACPI_FAILURE(status))
101 * The unit number could be derived from hdr->Sequence but we only
102 * support one HPET device.
104 hpet = (ACPI_TABLE_HPET *)hdr;
105 if (hpet->Sequence != 0)
106 printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
108 child = BUS_ADD_CHILD(parent, 0, "acpi_hpet", 0);
110 printf("%s: can't add child\n", __func__);
114 /* Record a magic value so we can detect this device later. */
115 acpi_set_magic(child, (uintptr_t)&acpi_hpet_devclass);
116 bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
118 if (device_probe_and_attach(child) != 0)
119 device_delete_child(parent, child);
123 acpi_hpet_probe(device_t dev)
125 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
127 if (acpi_disabled("hpet"))
129 if (!DEV_HPET(dev) &&
130 (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
131 device_get_unit(dev) != 0))
134 device_set_desc(dev, "High Precision Event Timer");
139 acpi_hpet_attach(device_t dev)
141 struct acpi_hpet_softc *sc;
146 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
148 sc = device_get_softc(dev);
150 sc->handle = acpi_get_handle(dev);
153 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
155 if (sc->mem_res == NULL)
158 /* Validate that we can access the whole region. */
159 if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
160 device_printf(dev, "memory region width %ld too small\n",
161 rman_get_size(sc->mem_res));
162 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
166 /* Be sure timer is enabled. */
167 bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
169 /* Read basic statistics about the timer. */
170 val = bus_read_4(sc->mem_res, HPET_OFFSET_PERIOD);
171 freq = (1000000000000000LL + val / 2) / val;
173 val = bus_read_4(sc->mem_res, HPET_OFFSET_INFO);
175 "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
176 val >> 16, val & 0xff, (val >> 18) & 0xf, freq,
177 ((val >> 15) & 1) ? " leg_route" : "",
178 ((val >> 13) & 1) ? " count_size" : "");
181 if (testenv("debug.acpi.hpet_test"))
185 * Don't attach if the timer never increments. Since the spec
186 * requires it to be at least 10 MHz, it has to change in 1 us.
188 val = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
190 val2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
192 device_printf(dev, "HPET never increments, disabling\n");
193 bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 0);
194 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
198 hpet_timecounter.tc_frequency = freq;
199 hpet_timecounter.tc_priv = sc;
200 tc_init(&hpet_timecounter);
206 acpi_hpet_detach(device_t dev)
208 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
210 /* XXX Without a tc_remove() function, we can't detach. */
215 acpi_hpet_resume(device_t dev)
217 struct acpi_hpet_softc *sc;
219 /* Re-enable the timer after a resume to keep the clock advancing. */
220 sc = device_get_softc(dev);
221 bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
226 /* Print some basic latency/rate information to assist in debugging. */
228 acpi_hpet_test(struct acpi_hpet_softc *sc)
232 struct bintime b0, b1, b2;
238 u1 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
239 for (i = 1; i < 1000; i++)
240 u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
242 u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
244 bintime_sub(&b2, &b1);
245 bintime_sub(&b1, &b0);
246 bintime_sub(&b2, &b1);
247 bintime2timespec(&b2, &ts);
249 device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
250 (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
252 device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
255 static device_method_t acpi_hpet_methods[] = {
256 /* Device interface */
257 DEVMETHOD(device_probe, acpi_hpet_probe),
258 DEVMETHOD(device_attach, acpi_hpet_attach),
259 DEVMETHOD(device_detach, acpi_hpet_detach),
260 DEVMETHOD(device_resume, acpi_hpet_resume),
265 static driver_t acpi_hpet_driver = {
268 sizeof(struct acpi_hpet_softc),
272 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
273 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);