xref: /freebsd/sys/dev/acpica/acpi_hpet.c (revision b3aaa0cc21c63d388230c7ef2a80abd631ff20d5)
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 	val &= ~HPET_CNF_LEG_RT;
87 	val |= HPET_CNF_ENABLE;
88 	bus_write_4(sc->mem_res, HPET_CONFIG, val);
89 }
90 
91 static void
92 hpet_disable(struct acpi_hpet_softc *sc)
93 {
94 	uint32_t val;
95 
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);
99 }
100 
101 /* Discover the HPET via the ACPI table of the same name. */
102 static void
103 acpi_hpet_identify(driver_t *driver, device_t parent)
104 {
105 	ACPI_TABLE_HPET *hpet;
106 	ACPI_TABLE_HEADER *hdr;
107 	ACPI_STATUS	status;
108 	device_t	child;
109 
110 	/* Only one HPET device can be added. */
111 	if (devclass_get_device(acpi_hpet_devclass, 0))
112 		return;
113 
114 	/* Currently, ID and minimum clock tick info is unused. */
115 
116 	status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
117 	if (ACPI_FAILURE(status))
118 		return;
119 
120 	/*
121 	 * The unit number could be derived from hdr->Sequence but we only
122 	 * support one HPET device.
123 	 */
124 	hpet = (ACPI_TABLE_HPET *)hdr;
125 	if (hpet->Sequence != 0)
126 		printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
127 		    hpet->Sequence);
128 	child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
129 	if (child == NULL) {
130 		printf("%s: can't add child\n", __func__);
131 		return;
132 	}
133 
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,
137 	    HPET_MEM_WIDTH);
138 }
139 
140 static int
141 acpi_hpet_probe(device_t dev)
142 {
143 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
144 
145 	if (acpi_disabled("hpet"))
146 		return (ENXIO);
147 	if (!DEV_HPET(dev) &&
148 	    (ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
149 	    device_get_unit(dev) != 0))
150 		return (ENXIO);
151 
152 	device_set_desc(dev, "High Precision Event Timer");
153 	return (0);
154 }
155 
156 static int
157 acpi_hpet_attach(device_t dev)
158 {
159 	struct acpi_hpet_softc *sc;
160 	int rid;
161 	uint32_t val, val2;
162 	uintmax_t freq;
163 
164 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
165 
166 	sc = device_get_softc(dev);
167 	sc->dev = dev;
168 	sc->handle = acpi_get_handle(dev);
169 
170 	rid = 0;
171 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
172 	    RF_ACTIVE);
173 	if (sc->mem_res == NULL)
174 		return (ENOMEM);
175 
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);
181 		return (ENXIO);
182 	}
183 
184 	/* Be sure timer is enabled. */
185 	hpet_enable(sc);
186 
187 	/* Read basic statistics about the timer. */
188 	val = bus_read_4(sc->mem_res, HPET_PERIOD);
189 	if (val == 0) {
190 		device_printf(dev, "invalid period\n");
191 		hpet_disable(sc);
192 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
193 		return (ENXIO);
194 	}
195 
196 	freq = (1000000000000000LL + val / 2) / val;
197 	if (bootverbose) {
198 		val = bus_read_4(sc->mem_res, HPET_CAPABILITIES);
199 		device_printf(dev,
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" : "");
205 	}
206 
207 	if (testenv("debug.acpi.hpet_test"))
208 		acpi_hpet_test(sc);
209 
210 	/*
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.
213 	 */
214 	val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
215 	DELAY(1);
216 	val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
217 	if (val == val2) {
218 		device_printf(dev, "HPET never increments, disabling\n");
219 		hpet_disable(sc);
220 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
221 		return (ENXIO);
222 	}
223 
224 	hpet_timecounter.tc_frequency = freq;
225 	hpet_timecounter.tc_priv = sc;
226 	tc_init(&hpet_timecounter);
227 
228 	return (0);
229 }
230 
231 static int
232 acpi_hpet_detach(device_t dev)
233 {
234 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
235 
236 	/* XXX Without a tc_remove() function, we can't detach. */
237 	return (EBUSY);
238 }
239 
240 static int
241 acpi_hpet_suspend(device_t dev)
242 {
243 	struct acpi_hpet_softc *sc;
244 
245 	/*
246 	 * Disable the timer during suspend.  The timer will not lose
247 	 * its state in S1 or S2, but we are required to disable
248 	 * it.
249 	 */
250 	sc = device_get_softc(dev);
251 	hpet_disable(sc);
252 
253 	return (0);
254 }
255 
256 static int
257 acpi_hpet_resume(device_t dev)
258 {
259 	struct acpi_hpet_softc *sc;
260 
261 	/* Re-enable the timer after a resume to keep the clock advancing. */
262 	sc = device_get_softc(dev);
263 	hpet_enable(sc);
264 
265 	return (0);
266 }
267 
268 /* Print some basic latency/rate information to assist in debugging. */
269 static void
270 acpi_hpet_test(struct acpi_hpet_softc *sc)
271 {
272 	int i;
273 	uint32_t u1, u2;
274 	struct bintime b0, b1, b2;
275 	struct timespec ts;
276 
277 	binuptime(&b0);
278 	binuptime(&b0);
279 	binuptime(&b1);
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);
283 	binuptime(&b2);
284 	u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
285 
286 	bintime_sub(&b2, &b1);
287 	bintime_sub(&b1, &b0);
288 	bintime_sub(&b2, &b1);
289 	bintime2timespec(&b2, &ts);
290 
291 	device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
292 	    (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
293 
294 	device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
295 }
296 
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),
305 
306 	{0, 0}
307 };
308 
309 static driver_t	acpi_hpet_driver = {
310 	"acpi_hpet",
311 	acpi_hpet_methods,
312 	sizeof(struct acpi_hpet_softc),
313 };
314 
315 
316 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
317 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);
318