xref: /freebsd/sys/dev/acpica/acpi_hpet.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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("$FreeBSD$");
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 #include <dev/acpica/acpi_hpet.h>
42 
43 ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
44 
45 static devclass_t acpi_hpet_devclass;
46 
47 /* ACPI CA debugging */
48 #define _COMPONENT	ACPI_TIMER
49 ACPI_MODULE_NAME("HPET")
50 
51 struct acpi_hpet_softc {
52 	device_t		dev;
53 	struct resource		*mem_res;
54 	ACPI_HANDLE		handle;
55 };
56 
57 static u_int hpet_get_timecount(struct timecounter *tc);
58 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
59 
60 static char *hpet_ids[] = { "PNP0103", NULL };
61 
62 #define DEV_HPET(x)	(acpi_get_magic(x) == (uintptr_t)&acpi_hpet_devclass)
63 
64 struct timecounter hpet_timecounter = {
65 	.tc_get_timecount =	hpet_get_timecount,
66 	.tc_counter_mask =	~0u,
67 	.tc_name =		"HPET",
68 	.tc_quality =		900,
69 };
70 
71 static u_int
72 hpet_get_timecount(struct timecounter *tc)
73 {
74 	struct acpi_hpet_softc *sc;
75 
76 	sc = tc->tc_priv;
77 	return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
78 }
79 
80 static void
81 hpet_enable(struct acpi_hpet_softc *sc)
82 {
83 	uint32_t val;
84 
85 	val = bus_read_4(sc->mem_res, HPET_CONFIG);
86 	bus_write_4(sc->mem_res, HPET_CONFIG, val | HPET_CNF_ENABLE);
87 }
88 
89 static void
90 hpet_disable(struct acpi_hpet_softc *sc)
91 {
92 	uint32_t val;
93 
94 	val = bus_read_4(sc->mem_res, HPET_CONFIG);
95 	bus_write_4(sc->mem_res, HPET_CONFIG, val & ~HPET_CNF_ENABLE);
96 }
97 
98 /* Discover the HPET via the ACPI table of the same name. */
99 static void
100 acpi_hpet_identify(driver_t *driver, device_t parent)
101 {
102 	ACPI_TABLE_HPET *hpet;
103 	ACPI_TABLE_HEADER *hdr;
104 	ACPI_STATUS	status;
105 	device_t	child;
106 
107 	/* Only one HPET device can be added. */
108 	if (devclass_get_device(acpi_hpet_devclass, 0))
109 		return;
110 
111 	/* Currently, ID and minimum clock tick info is unused. */
112 
113 	status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
114 	if (ACPI_FAILURE(status))
115 		return;
116 
117 	/*
118 	 * The unit number could be derived from hdr->Sequence but we only
119 	 * support one HPET device.
120 	 */
121 	hpet = (ACPI_TABLE_HPET *)hdr;
122 	if (hpet->Sequence != 0)
123 		printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
124 		    hpet->Sequence);
125 	child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
126 	if (child == NULL) {
127 		printf("%s: can't add child\n", __func__);
128 		return;
129 	}
130 
131 	/* Record a magic value so we can detect this device later. */
132 	acpi_set_magic(child, (uintptr_t)&acpi_hpet_devclass);
133 	bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
134 	    HPET_MEM_WIDTH);
135 }
136 
137 static int
138 acpi_hpet_probe(device_t dev)
139 {
140 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
141 
142 	if (acpi_disabled("hpet"))
143 		return (ENXIO);
144 	if (!DEV_HPET(dev) &&
145 	    (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
146 	    device_get_unit(dev) != 0))
147 		return (ENXIO);
148 
149 	device_set_desc(dev, "High Precision Event Timer");
150 	return (0);
151 }
152 
153 static int
154 acpi_hpet_attach(device_t dev)
155 {
156 	struct acpi_hpet_softc *sc;
157 	int rid;
158 	uint32_t val, val2;
159 	uintmax_t freq;
160 
161 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
162 
163 	sc = device_get_softc(dev);
164 	sc->dev = dev;
165 	sc->handle = acpi_get_handle(dev);
166 
167 	rid = 0;
168 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
169 	    RF_ACTIVE);
170 	if (sc->mem_res == NULL)
171 		return (ENOMEM);
172 
173 	/* Validate that we can access the whole region. */
174 	if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
175 		device_printf(dev, "memory region width %ld too small\n",
176 		    rman_get_size(sc->mem_res));
177 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
178 		return (ENXIO);
179 	}
180 
181 	/* Be sure timer is enabled. */
182 	hpet_enable(sc);
183 
184 	/* Read basic statistics about the timer. */
185 	val = bus_read_4(sc->mem_res, HPET_PERIOD);
186 	if (val == 0) {
187 		device_printf(dev, "invalid period\n");
188 		hpet_disable(sc);
189 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
190 		return (ENXIO);
191 	}
192 
193 	freq = (1000000000000000LL + val / 2) / val;
194 	if (bootverbose) {
195 		val = bus_read_4(sc->mem_res, HPET_CAPABILITIES);
196 		device_printf(dev,
197 		    "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
198 		    val >> 16, val & HPET_CAP_REV_ID,
199 		    (val & HPET_CAP_NUM_TIM) >> 8, freq,
200 		    (val & HPET_CAP_LEG_RT) ? " legacy_route" : "",
201 		    (val & HPET_CAP_COUNT_SIZE) ? " 64-bit" : "");
202 	}
203 
204 	if (testenv("debug.acpi.hpet_test"))
205 		acpi_hpet_test(sc);
206 
207 	/*
208 	 * Don't attach if the timer never increments.  Since the spec
209 	 * requires it to be at least 10 MHz, it has to change in 1 us.
210 	 */
211 	val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
212 	DELAY(1);
213 	val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
214 	if (val == val2) {
215 		device_printf(dev, "HPET never increments, disabling\n");
216 		hpet_disable(sc);
217 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
218 		return (ENXIO);
219 	}
220 
221 	hpet_timecounter.tc_frequency = freq;
222 	hpet_timecounter.tc_priv = sc;
223 	tc_init(&hpet_timecounter);
224 
225 	return (0);
226 }
227 
228 static int
229 acpi_hpet_detach(device_t dev)
230 {
231 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
232 
233 	/* XXX Without a tc_remove() function, we can't detach. */
234 	return (EBUSY);
235 }
236 
237 static int
238 acpi_hpet_suspend(device_t dev)
239 {
240 	struct acpi_hpet_softc *sc;
241 
242 	/*
243 	 * Disable the timer during suspend.  The timer will not lose
244 	 * its state in S1 or S2, but we are required to disable
245 	 * it.
246 	 */
247 	sc = device_get_softc(dev);
248 	hpet_disable(sc);
249 
250 	return (0);
251 }
252 
253 static int
254 acpi_hpet_resume(device_t dev)
255 {
256 	struct acpi_hpet_softc *sc;
257 
258 	/* Re-enable the timer after a resume to keep the clock advancing. */
259 	sc = device_get_softc(dev);
260 	hpet_enable(sc);
261 
262 	return (0);
263 }
264 
265 /* Print some basic latency/rate information to assist in debugging. */
266 static void
267 acpi_hpet_test(struct acpi_hpet_softc *sc)
268 {
269 	int i;
270 	uint32_t u1, u2;
271 	struct bintime b0, b1, b2;
272 	struct timespec ts;
273 
274 	binuptime(&b0);
275 	binuptime(&b0);
276 	binuptime(&b1);
277 	u1 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
278 	for (i = 1; i < 1000; i++)
279 		u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
280 	binuptime(&b2);
281 	u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
282 
283 	bintime_sub(&b2, &b1);
284 	bintime_sub(&b1, &b0);
285 	bintime_sub(&b2, &b1);
286 	bintime2timespec(&b2, &ts);
287 
288 	device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
289 	    (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
290 
291 	device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
292 }
293 
294 static device_method_t acpi_hpet_methods[] = {
295 	/* Device interface */
296 	DEVMETHOD(device_identify, acpi_hpet_identify),
297 	DEVMETHOD(device_probe, acpi_hpet_probe),
298 	DEVMETHOD(device_attach, acpi_hpet_attach),
299 	DEVMETHOD(device_detach, acpi_hpet_detach),
300 	DEVMETHOD(device_suspend, acpi_hpet_suspend),
301 	DEVMETHOD(device_resume, acpi_hpet_resume),
302 
303 	{0, 0}
304 };
305 
306 static driver_t	acpi_hpet_driver = {
307 	"acpi_hpet",
308 	acpi_hpet_methods,
309 	sizeof(struct acpi_hpet_softc),
310 };
311 
312 
313 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
314 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);
315