acpi_hpet.c revision 193530 
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 193530 2009-06-05 18:44:36Z jkim $");
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/include/acpi.h>
40#include <contrib/dev/acpica/include/accommon.h>
41
42#include <dev/acpica/acpivar.h>
43#include <dev/acpica/acpi_hpet.h>
44
45ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
46
47static devclass_t acpi_hpet_devclass;
48
49/* ACPI CA debugging */
50#define _COMPONENT	ACPI_TIMER
51ACPI_MODULE_NAME("HPET")
52
53struct acpi_hpet_softc {
54	device_t		dev;
55	struct resource		*mem_res;
56	ACPI_HANDLE		handle;
57};
58
59static u_int hpet_get_timecount(struct timecounter *tc);
60static void acpi_hpet_test(struct acpi_hpet_softc *sc);
61
62static char *hpet_ids[] = { "PNP0103", NULL };
63
64#define DEV_HPET(x)	(acpi_get_magic(x) == (uintptr_t)&acpi_hpet_devclass)
65
66struct timecounter hpet_timecounter = {
67	.tc_get_timecount =	hpet_get_timecount,
68	.tc_counter_mask =	~0u,
69	.tc_name =		"HPET",
70	.tc_quality =		900,
71};
72
73static u_int
74hpet_get_timecount(struct timecounter *tc)
75{
76	struct acpi_hpet_softc *sc;
77
78	sc = tc->tc_priv;
79	return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
80}
81
82static void
83hpet_enable(struct acpi_hpet_softc *sc)
84{
85	uint32_t val;
86
87	val = bus_read_4(sc->mem_res, HPET_CONFIG);
88	val &= ~HPET_CNF_LEG_RT;
89	val |= HPET_CNF_ENABLE;
90	bus_write_4(sc->mem_res, HPET_CONFIG, val);
91}
92
93static void
94hpet_disable(struct acpi_hpet_softc *sc)
95{
96	uint32_t val;
97
98	val = bus_read_4(sc->mem_res, HPET_CONFIG);
99	val &= ~HPET_CNF_ENABLE;
100	bus_write_4(sc->mem_res, HPET_CONFIG, val);
101}
102
103/* Discover the HPET via the ACPI table of the same name. */
104static void
105acpi_hpet_identify(driver_t *driver, device_t parent)
106{
107	ACPI_TABLE_HPET *hpet;
108	ACPI_TABLE_HEADER *hdr;
109	ACPI_STATUS	status;
110	device_t	child;
111
112	/* Only one HPET device can be added. */
113	if (devclass_get_device(acpi_hpet_devclass, 0))
114		return;
115
116	/* Currently, ID and minimum clock tick info is unused. */
117
118	status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
119	if (ACPI_FAILURE(status))
120		return;
121
122	/*
123	 * The unit number could be derived from hdr->Sequence but we only
124	 * support one HPET device.
125	 */
126	hpet = (ACPI_TABLE_HPET *)hdr;
127	if (hpet->Sequence != 0)
128		printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
129		    hpet->Sequence);
130	child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
131	if (child == NULL) {
132		printf("%s: can't add child\n", __func__);
133		return;
134	}
135
136	/* Record a magic value so we can detect this device later. */
137	acpi_set_magic(child, (uintptr_t)&acpi_hpet_devclass);
138	bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
139	    HPET_MEM_WIDTH);
140}
141
142static int
143acpi_hpet_probe(device_t dev)
144{
145	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
146
147	if (acpi_disabled("hpet"))
148		return (ENXIO);
149	if (!DEV_HPET(dev) &&
150	    (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
151	    device_get_unit(dev) != 0))
152		return (ENXIO);
153
154	device_set_desc(dev, "High Precision Event Timer");
155	return (0);
156}
157
158static int
159acpi_hpet_attach(device_t dev)
160{
161	struct acpi_hpet_softc *sc;
162	int rid;
163	uint32_t val, val2;
164	uintmax_t freq;
165
166	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
167
168	sc = device_get_softc(dev);
169	sc->dev = dev;
170	sc->handle = acpi_get_handle(dev);
171
172	rid = 0;
173	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
174	    RF_ACTIVE);
175	if (sc->mem_res == NULL)
176		return (ENOMEM);
177
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);
183		return (ENXIO);
184	}
185
186	/* Be sure timer is enabled. */
187	hpet_enable(sc);
188
189	/* Read basic statistics about the timer. */
190	val = bus_read_4(sc->mem_res, HPET_PERIOD);
191	if (val == 0) {
192		device_printf(dev, "invalid period\n");
193		hpet_disable(sc);
194		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
195		return (ENXIO);
196	}
197
198	freq = (1000000000000000LL + val / 2) / val;
199	if (bootverbose) {
200		val = bus_read_4(sc->mem_res, HPET_CAPABILITIES);
201		device_printf(dev,
202		    "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
203		    val >> 16, val & HPET_CAP_REV_ID,
204		    (val & HPET_CAP_NUM_TIM) >> 8, freq,
205		    (val & HPET_CAP_LEG_RT) ? " legacy_route" : "",
206		    (val & HPET_CAP_COUNT_SIZE) ? " 64-bit" : "");
207	}
208
209	if (testenv("debug.acpi.hpet_test"))
210		acpi_hpet_test(sc);
211
212	/*
213	 * Don't attach if the timer never increments.  Since the spec
214	 * requires it to be at least 10 MHz, it has to change in 1 us.
215	 */
216	val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
217	DELAY(1);
218	val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
219	if (val == val2) {
220		device_printf(dev, "HPET never increments, disabling\n");
221		hpet_disable(sc);
222		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
223		return (ENXIO);
224	}
225
226	hpet_timecounter.tc_frequency = freq;
227	hpet_timecounter.tc_priv = sc;
228	tc_init(&hpet_timecounter);
229
230	return (0);
231}
232
233static int
234acpi_hpet_detach(device_t dev)
235{
236	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
237
238	/* XXX Without a tc_remove() function, we can't detach. */
239	return (EBUSY);
240}
241
242static int
243acpi_hpet_suspend(device_t dev)
244{
245	struct acpi_hpet_softc *sc;
246
247	/*
248	 * Disable the timer during suspend.  The timer will not lose
249	 * its state in S1 or S2, but we are required to disable
250	 * it.
251	 */
252	sc = device_get_softc(dev);
253	hpet_disable(sc);
254
255	return (0);
256}
257
258static int
259acpi_hpet_resume(device_t dev)
260{
261	struct acpi_hpet_softc *sc;
262
263	/* Re-enable the timer after a resume to keep the clock advancing. */
264	sc = device_get_softc(dev);
265	hpet_enable(sc);
266
267	return (0);
268}
269
270/* Print some basic latency/rate information to assist in debugging. */
271static void
272acpi_hpet_test(struct acpi_hpet_softc *sc)
273{
274	int i;
275	uint32_t u1, u2;
276	struct bintime b0, b1, b2;
277	struct timespec ts;
278
279	binuptime(&b0);
280	binuptime(&b0);
281	binuptime(&b1);
282	u1 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
283	for (i = 1; i < 1000; i++)
284		u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
285	binuptime(&b2);
286	u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
287
288	bintime_sub(&b2, &b1);
289	bintime_sub(&b1, &b0);
290	bintime_sub(&b2, &b1);
291	bintime2timespec(&b2, &ts);
292
293	device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
294	    (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
295
296	device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
297}
298
299static device_method_t acpi_hpet_methods[] = {
300	/* Device interface */
301	DEVMETHOD(device_identify, acpi_hpet_identify),
302	DEVMETHOD(device_probe, acpi_hpet_probe),
303	DEVMETHOD(device_attach, acpi_hpet_attach),
304	DEVMETHOD(device_detach, acpi_hpet_detach),
305	DEVMETHOD(device_suspend, acpi_hpet_suspend),
306	DEVMETHOD(device_resume, acpi_hpet_resume),
307
308	{0, 0}
309};
310
311static driver_t	acpi_hpet_driver = {
312	"acpi_hpet",
313	acpi_hpet_methods,
314	sizeof(struct acpi_hpet_softc),
315};
316
317
318DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
319MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);
320