acpi_hpet.c revision 170783 
1/*-
2 * Copyright (c) 2005 Poul-Henning Kamp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/dev/acpica/acpi_hpet.c 170783 2007-06-15 18:02:34Z njl $");
29
30#include "opt_acpi.h"
31#include <sys/param.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/module.h>
35#include <sys/rman.h>
36#include <sys/time.h>
37#include <sys/timetc.h>
38
39#include <contrib/dev/acpica/acpi.h>
40#include <dev/acpica/acpivar.h>
41
42ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
43
44static devclass_t acpi_hpet_devclass;
45
46/* ACPI CA debugging */
47#define _COMPONENT	ACPI_TIMER
48ACPI_MODULE_NAME("HPET")
49
50struct acpi_hpet_softc {
51	device_t		dev;
52	struct resource		*mem_res;
53	ACPI_HANDLE		handle;
54};
55
56static u_int hpet_get_timecount(struct timecounter *tc);
57static void acpi_hpet_test(struct acpi_hpet_softc *sc);
58
59static char *hpet_ids[] = { "PNP0103", NULL };
60
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 */
66
67#define DEV_HPET(x)	(acpi_get_magic(x) == (uintptr_t)&acpi_hpet_devclass)
68
69struct timecounter hpet_timecounter = {
70	.tc_get_timecount =	hpet_get_timecount,
71	.tc_counter_mask =	~0u,
72	.tc_name =		"HPET",
73	.tc_quality =		2000,
74};
75
76static u_int
77hpet_get_timecount(struct timecounter *tc)
78{
79	struct acpi_hpet_softc *sc;
80
81	sc = tc->tc_priv;
82	return (bus_read_4(sc->mem_res, HPET_OFFSET_VALUE));
83}
84
85/* Discover the HPET via the ACPI table of the same name. */
86void
87acpi_hpet_table_probe(device_t parent)
88{
89	ACPI_TABLE_HPET *hpet;
90	ACPI_TABLE_HEADER *hdr;
91	ACPI_STATUS	status;
92	device_t	child;
93
94	/* Currently, ID and minimum clock tick info is unused. */
95
96	status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
97	if (ACPI_FAILURE(status))
98		return;
99
100	/*
101	 * The unit number could be derived from hdr->Sequence but we only
102	 * support one HPET device.
103	 */
104	hpet = (ACPI_TABLE_HPET *)hdr;
105	if (hpet->Sequence != 0)
106		printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
107		    hpet->Sequence);
108	child = BUS_ADD_CHILD(parent, 0, "acpi_hpet", 0);
109	if (child == NULL) {
110		printf("%s: can't add child\n", __func__);
111		return;
112	}
113
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,
117	    HPET_MEM_WIDTH);
118	if (device_probe_and_attach(child) != 0)
119		device_delete_child(parent, child);
120}
121
122static int
123acpi_hpet_probe(device_t dev)
124{
125	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
126
127	if (acpi_disabled("hpet"))
128		return (ENXIO);
129	if (!DEV_HPET(dev) &&
130	    (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
131	    device_get_unit(dev) != 0))
132		return (ENXIO);
133
134	device_set_desc(dev, "High Precision Event Timer");
135	return (0);
136}
137
138static int
139acpi_hpet_attach(device_t dev)
140{
141	struct acpi_hpet_softc *sc;
142	int rid;
143	uint32_t val;
144	uintmax_t freq;
145
146	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
147
148	sc = device_get_softc(dev);
149	sc->dev = dev;
150	sc->handle = acpi_get_handle(dev);
151
152	rid = 0;
153	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
154	    RF_ACTIVE);
155	if (sc->mem_res == NULL)
156		return (ENOMEM);
157
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);
163		return (ENXIO);
164	}
165
166	/* Read basic statistics about the timer. */
167	val = bus_read_4(sc->mem_res, HPET_OFFSET_PERIOD);
168	freq = (1000000000000000LL + val / 2) / val;
169	if (bootverbose) {
170		val = bus_read_4(sc->mem_res, HPET_OFFSET_INFO);
171		device_printf(dev,
172		    "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
173		    val >> 16, val & 0xff, (val >> 18) & 0xf, freq,
174		    ((val >> 15) & 1) ? " leg_route" : "",
175		    ((val >> 13) & 1) ? " count_size" : "");
176	}
177
178	/* Be sure it is enabled. */
179	bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
180
181	if (testenv("debug.acpi.hpet_test"))
182		acpi_hpet_test(sc);
183
184	hpet_timecounter.tc_frequency = freq;
185	hpet_timecounter.tc_priv = sc;
186	tc_init(&hpet_timecounter);
187
188	return (0);
189}
190
191static int
192acpi_hpet_detach(device_t dev)
193{
194	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
195
196	/* XXX Without a tc_remove() function, we can't detach. */
197	return (EBUSY);
198}
199
200static int
201acpi_hpet_resume(device_t dev)
202{
203	struct acpi_hpet_softc *sc;
204
205	/* Re-enable the timer after a resume to keep the clock advancing. */
206	sc = device_get_softc(dev);
207	bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
208
209	return (0);
210}
211
212/* Print some basic latency/rate information to assist in debugging. */
213static void
214acpi_hpet_test(struct acpi_hpet_softc *sc)
215{
216	int i;
217	uint32_t u1, u2;
218	struct bintime b0, b1, b2;
219	struct timespec ts;
220
221	binuptime(&b0);
222	binuptime(&b0);
223	binuptime(&b1);
224	u1 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
225	for (i = 1; i < 1000; i++)
226		u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
227	binuptime(&b2);
228	u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
229
230	bintime_sub(&b2, &b1);
231	bintime_sub(&b1, &b0);
232	bintime_sub(&b2, &b1);
233	bintime2timespec(&b2, &ts);
234
235	device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
236	    (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
237
238	device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
239}
240
241static device_method_t acpi_hpet_methods[] = {
242	/* Device interface */
243	DEVMETHOD(device_probe, acpi_hpet_probe),
244	DEVMETHOD(device_attach, acpi_hpet_attach),
245	DEVMETHOD(device_detach, acpi_hpet_detach),
246	DEVMETHOD(device_resume, acpi_hpet_resume),
247
248	{0, 0}
249};
250
251static driver_t	acpi_hpet_driver = {
252	"acpi_hpet",
253	acpi_hpet_methods,
254	sizeof(struct acpi_hpet_softc),
255};
256
257
258DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
259MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);
260