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>
41 #include <dev/acpica/acpi_hpet.h>
43 ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
45 static devclass_t acpi_hpet_devclass;
47 /* ACPI CA debugging */
48 #define _COMPONENT ACPI_TIMER
49 ACPI_MODULE_NAME("HPET")
51 struct acpi_hpet_softc {
53 struct resource *mem_res;
57 static u_int hpet_get_timecount(struct timecounter *tc);
58 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
60 static char *hpet_ids[] = { "PNP0103", NULL };
62 #define DEV_HPET(x) (acpi_get_magic(x) == (uintptr_t)&acpi_hpet_devclass)
64 struct timecounter hpet_timecounter = {
65 .tc_get_timecount = hpet_get_timecount,
66 .tc_counter_mask = ~0u,
72 hpet_get_timecount(struct timecounter *tc)
74 struct acpi_hpet_softc *sc;
77 return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
81 hpet_enable(struct acpi_hpet_softc *sc)
85 val = bus_read_4(sc->mem_res, HPET_CONFIG);
86 val &= ~HPET_CNF_LEG_RT;
87 val |= HPET_CNF_ENABLE;
88 bus_write_4(sc->mem_res, HPET_CONFIG, val);
92 hpet_disable(struct acpi_hpet_softc *sc)
96 val = bus_read_4(sc->mem_res, HPET_CONFIG);
97 val &= ~HPET_CNF_ENABLE;
98 bus_write_4(sc->mem_res, HPET_CONFIG, val);
101 /* Discover the HPET via the ACPI table of the same name. */
103 acpi_hpet_identify(driver_t *driver, device_t parent)
105 ACPI_TABLE_HPET *hpet;
106 ACPI_TABLE_HEADER *hdr;
110 /* Only one HPET device can be added. */
111 if (devclass_get_device(acpi_hpet_devclass, 0))
114 /* Currently, ID and minimum clock tick info is unused. */
116 status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
117 if (ACPI_FAILURE(status))
121 * The unit number could be derived from hdr->Sequence but we only
122 * support one HPET device.
124 hpet = (ACPI_TABLE_HPET *)hdr;
125 if (hpet->Sequence != 0)
126 printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
128 child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
130 printf("%s: can't add child\n", __func__);
134 /* Record a magic value so we can detect this device later. */
135 acpi_set_magic(child, (uintptr_t)&acpi_hpet_devclass);
136 bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
141 acpi_hpet_probe(device_t dev)
143 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
145 if (acpi_disabled("hpet"))
147 if (!DEV_HPET(dev) &&
148 (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
149 device_get_unit(dev) != 0))
152 device_set_desc(dev, "High Precision Event Timer");
157 acpi_hpet_attach(device_t dev)
159 struct acpi_hpet_softc *sc;
164 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
166 sc = device_get_softc(dev);
168 sc->handle = acpi_get_handle(dev);
171 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
173 if (sc->mem_res == NULL)
176 /* Validate that we can access the whole region. */
177 if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
178 device_printf(dev, "memory region width %ld too small\n",
179 rman_get_size(sc->mem_res));
180 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
184 /* Be sure timer is enabled. */
187 /* Read basic statistics about the timer. */
188 val = bus_read_4(sc->mem_res, HPET_PERIOD);
190 device_printf(dev, "invalid period\n");
192 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
196 freq = (1000000000000000LL + val / 2) / val;
198 val = bus_read_4(sc->mem_res, HPET_CAPABILITIES);
200 "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
201 val >> 16, val & HPET_CAP_REV_ID,
202 (val & HPET_CAP_NUM_TIM) >> 8, freq,
203 (val & HPET_CAP_LEG_RT) ? " legacy_route" : "",
204 (val & HPET_CAP_COUNT_SIZE) ? " 64-bit" : "");
207 if (testenv("debug.acpi.hpet_test"))
211 * Don't attach if the timer never increments. Since the spec
212 * requires it to be at least 10 MHz, it has to change in 1 us.
214 val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
216 val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
218 device_printf(dev, "HPET never increments, disabling\n");
220 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
224 hpet_timecounter.tc_frequency = freq;
225 hpet_timecounter.tc_priv = sc;
226 tc_init(&hpet_timecounter);
232 acpi_hpet_detach(device_t dev)
234 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
236 /* XXX Without a tc_remove() function, we can't detach. */
241 acpi_hpet_suspend(device_t dev)
243 struct acpi_hpet_softc *sc;
246 * Disable the timer during suspend. The timer will not lose
247 * its state in S1 or S2, but we are required to disable
250 sc = device_get_softc(dev);
257 acpi_hpet_resume(device_t dev)
259 struct acpi_hpet_softc *sc;
261 /* Re-enable the timer after a resume to keep the clock advancing. */
262 sc = device_get_softc(dev);
268 /* Print some basic latency/rate information to assist in debugging. */
270 acpi_hpet_test(struct acpi_hpet_softc *sc)
274 struct bintime b0, b1, b2;
280 u1 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
281 for (i = 1; i < 1000; i++)
282 u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
284 u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
286 bintime_sub(&b2, &b1);
287 bintime_sub(&b1, &b0);
288 bintime_sub(&b2, &b1);
289 bintime2timespec(&b2, &ts);
291 device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
292 (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
294 device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
297 static device_method_t acpi_hpet_methods[] = {
298 /* Device interface */
299 DEVMETHOD(device_identify, acpi_hpet_identify),
300 DEVMETHOD(device_probe, acpi_hpet_probe),
301 DEVMETHOD(device_attach, acpi_hpet_attach),
302 DEVMETHOD(device_detach, acpi_hpet_detach),
303 DEVMETHOD(device_suspend, acpi_hpet_suspend),
304 DEVMETHOD(device_resume, acpi_hpet_resume),
309 static driver_t acpi_hpet_driver = {
312 sizeof(struct acpi_hpet_softc),
316 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
317 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);