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/include/acpi.h>
40 #include <contrib/dev/acpica/include/accommon.h>
42 #include <dev/acpica/acpivar.h>
43 #include <dev/acpica/acpi_hpet.h>
45 #define HPET_VENDID_AMD 0x4353
46 #define HPET_VENDID_INTEL 0x8086
48 ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
50 static devclass_t acpi_hpet_devclass;
52 /* ACPI CA debugging */
53 #define _COMPONENT ACPI_TIMER
54 ACPI_MODULE_NAME("HPET")
56 struct acpi_hpet_softc {
58 struct resource *mem_res;
62 static u_int hpet_get_timecount(struct timecounter *tc);
63 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
65 static char *hpet_ids[] = { "PNP0103", NULL };
67 struct timecounter hpet_timecounter = {
68 .tc_get_timecount = hpet_get_timecount,
69 .tc_counter_mask = ~0u,
75 hpet_get_timecount(struct timecounter *tc)
77 struct acpi_hpet_softc *sc;
80 return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
84 hpet_enable(struct acpi_hpet_softc *sc)
88 val = bus_read_4(sc->mem_res, HPET_CONFIG);
89 val &= ~HPET_CNF_LEG_RT;
90 val |= HPET_CNF_ENABLE;
91 bus_write_4(sc->mem_res, HPET_CONFIG, val);
95 hpet_disable(struct acpi_hpet_softc *sc)
99 val = bus_read_4(sc->mem_res, HPET_CONFIG);
100 val &= ~HPET_CNF_ENABLE;
101 bus_write_4(sc->mem_res, HPET_CONFIG, val);
104 /* Discover the HPET via the ACPI table of the same name. */
106 acpi_hpet_identify(driver_t *driver, device_t parent)
108 ACPI_TABLE_HPET *hpet;
109 ACPI_TABLE_HEADER *hdr;
113 /* Only one HPET device can be added. */
114 if (devclass_get_device(acpi_hpet_devclass, 0))
117 /* Currently, ID and minimum clock tick info is unused. */
119 status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
120 if (ACPI_FAILURE(status))
124 * The unit number could be derived from hdr->Sequence but we only
125 * support one HPET device.
127 hpet = (ACPI_TABLE_HPET *)hdr;
128 if (hpet->Sequence != 0)
129 printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
131 child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
133 printf("%s: can't add child\n", __func__);
137 bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
142 acpi_hpet_probe(device_t dev)
144 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
146 if (acpi_disabled("hpet"))
148 if (acpi_get_handle(dev) != NULL &&
149 (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
150 device_get_unit(dev) != 0))
153 device_set_desc(dev, "High Precision Event Timer");
158 acpi_hpet_attach(device_t dev)
160 struct acpi_hpet_softc *sc;
166 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
168 sc = device_get_softc(dev);
170 sc->handle = acpi_get_handle(dev);
173 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
175 if (sc->mem_res == NULL)
178 /* Validate that we can access the whole region. */
179 if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
180 device_printf(dev, "memory region width %ld too small\n",
181 rman_get_size(sc->mem_res));
182 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
186 /* Be sure timer is enabled. */
189 /* Read basic statistics about the timer. */
190 val = bus_read_4(sc->mem_res, HPET_PERIOD);
192 device_printf(dev, "invalid period\n");
194 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
198 freq = (1000000000000000LL + val / 2) / val;
200 val = bus_read_4(sc->mem_res, HPET_CAPABILITIES);
203 * ATI/AMD violates IA-PC HPET (High Precision Event Timers)
204 * Specification and provides an off by one number
205 * of timers/comparators.
206 * Additionally, they use unregistered value in VENDOR_ID field.
208 num_timers = 1 + ((val & HPET_CAP_NUM_TIM) >> 8);
210 if (vendor == HPET_VENDID_AMD && num_timers > 0)
213 "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
214 vendor, val & HPET_CAP_REV_ID,
216 (val & HPET_CAP_LEG_RT) ? " legacy_route" : "",
217 (val & HPET_CAP_COUNT_SIZE) ? " 64-bit" : "");
220 if (testenv("debug.acpi.hpet_test"))
224 * Don't attach if the timer never increments. Since the spec
225 * requires it to be at least 10 MHz, it has to change in 1 us.
227 val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
229 val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
231 device_printf(dev, "HPET never increments, disabling\n");
233 bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
237 hpet_timecounter.tc_frequency = freq;
238 hpet_timecounter.tc_priv = sc;
239 tc_init(&hpet_timecounter);
245 acpi_hpet_detach(device_t dev)
247 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
249 /* XXX Without a tc_remove() function, we can't detach. */
254 acpi_hpet_suspend(device_t dev)
256 struct acpi_hpet_softc *sc;
259 * Disable the timer during suspend. The timer will not lose
260 * its state in S1 or S2, but we are required to disable
263 sc = device_get_softc(dev);
270 acpi_hpet_resume(device_t dev)
272 struct acpi_hpet_softc *sc;
274 /* Re-enable the timer after a resume to keep the clock advancing. */
275 sc = device_get_softc(dev);
281 /* Print some basic latency/rate information to assist in debugging. */
283 acpi_hpet_test(struct acpi_hpet_softc *sc)
287 struct bintime b0, b1, b2;
293 u1 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
294 for (i = 1; i < 1000; i++)
295 u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
297 u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
299 bintime_sub(&b2, &b1);
300 bintime_sub(&b1, &b0);
301 bintime_sub(&b2, &b1);
302 bintime2timespec(&b2, &ts);
304 device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
305 (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
307 device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
310 static device_method_t acpi_hpet_methods[] = {
311 /* Device interface */
312 DEVMETHOD(device_identify, acpi_hpet_identify),
313 DEVMETHOD(device_probe, acpi_hpet_probe),
314 DEVMETHOD(device_attach, acpi_hpet_attach),
315 DEVMETHOD(device_detach, acpi_hpet_detach),
316 DEVMETHOD(device_suspend, acpi_hpet_suspend),
317 DEVMETHOD(device_resume, acpi_hpet_resume),
322 static driver_t acpi_hpet_driver = {
325 sizeof(struct acpi_hpet_softc),
329 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
330 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);