xref: /freebsd/sys/dev/acpica/acpi_hpet.c (revision d8b878873e7aa8df1972cc6a642804b17eb61087)
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/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 
45 #define HPET_VENDID_AMD		0x4353
46 #define HPET_VENDID_INTEL	0x8086
47 
48 ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
49 
50 static devclass_t acpi_hpet_devclass;
51 
52 /* ACPI CA debugging */
53 #define _COMPONENT	ACPI_TIMER
54 ACPI_MODULE_NAME("HPET")
55 
56 struct acpi_hpet_softc {
57 	device_t		dev;
58 	struct resource		*mem_res;
59 	ACPI_HANDLE		handle;
60 };
61 
62 static u_int hpet_get_timecount(struct timecounter *tc);
63 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
64 
65 static char *hpet_ids[] = { "PNP0103", NULL };
66 
67 struct timecounter hpet_timecounter = {
68 	.tc_get_timecount =	hpet_get_timecount,
69 	.tc_counter_mask =	~0u,
70 	.tc_name =		"HPET",
71 	.tc_quality =		900,
72 };
73 
74 static u_int
75 hpet_get_timecount(struct timecounter *tc)
76 {
77 	struct acpi_hpet_softc *sc;
78 
79 	sc = tc->tc_priv;
80 	return (bus_read_4(sc->mem_res, HPET_MAIN_COUNTER));
81 }
82 
83 static void
84 hpet_enable(struct acpi_hpet_softc *sc)
85 {
86 	uint32_t val;
87 
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);
92 }
93 
94 static void
95 hpet_disable(struct acpi_hpet_softc *sc)
96 {
97 	uint32_t val;
98 
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);
102 }
103 
104 /* Discover the HPET via the ACPI table of the same name. */
105 static void
106 acpi_hpet_identify(driver_t *driver, device_t parent)
107 {
108 	ACPI_TABLE_HPET *hpet;
109 	ACPI_TABLE_HEADER *hdr;
110 	ACPI_STATUS	status;
111 	device_t	child;
112 
113 	/* Only one HPET device can be added. */
114 	if (devclass_get_device(acpi_hpet_devclass, 0))
115 		return;
116 
117 	/* Currently, ID and minimum clock tick info is unused. */
118 
119 	status = AcpiGetTable(ACPI_SIG_HPET, 1, (ACPI_TABLE_HEADER **)&hdr);
120 	if (ACPI_FAILURE(status))
121 		return;
122 
123 	/*
124 	 * The unit number could be derived from hdr->Sequence but we only
125 	 * support one HPET device.
126 	 */
127 	hpet = (ACPI_TABLE_HPET *)hdr;
128 	if (hpet->Sequence != 0)
129 		printf("ACPI HPET table warning: Sequence is non-zero (%d)\n",
130 		    hpet->Sequence);
131 	child = BUS_ADD_CHILD(parent, ACPI_DEV_BASE_ORDER, "acpi_hpet", 0);
132 	if (child == NULL) {
133 		printf("%s: can't add child\n", __func__);
134 		return;
135 	}
136 
137 	bus_set_resource(child, SYS_RES_MEMORY, 0, hpet->Address.Address,
138 	    HPET_MEM_WIDTH);
139 }
140 
141 static int
142 acpi_hpet_probe(device_t dev)
143 {
144 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
145 
146 	if (acpi_disabled("hpet"))
147 		return (ENXIO);
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))
151 		return (ENXIO);
152 
153 	device_set_desc(dev, "High Precision Event Timer");
154 	return (0);
155 }
156 
157 static int
158 acpi_hpet_attach(device_t dev)
159 {
160 	struct acpi_hpet_softc *sc;
161 	int rid, num_timers;
162 	uint32_t val, val2;
163 	uintmax_t freq;
164 	uint16_t vendor;
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 
202 		/*
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.
207 		 */
208 		num_timers = 1 + ((val & HPET_CAP_NUM_TIM) >> 8);
209 		vendor = val >> 16;
210 		if (vendor == HPET_VENDID_AMD && num_timers > 0)
211 			num_timers--;
212 		device_printf(dev,
213 		    "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
214 		    vendor, val & HPET_CAP_REV_ID,
215 		    num_timers, freq,
216 		    (val & HPET_CAP_LEG_RT) ? " legacy_route" : "",
217 		    (val & HPET_CAP_COUNT_SIZE) ? " 64-bit" : "");
218 	}
219 
220 	if (testenv("debug.acpi.hpet_test"))
221 		acpi_hpet_test(sc);
222 
223 	/*
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.
226 	 */
227 	val = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
228 	DELAY(1);
229 	val2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
230 	if (val == val2) {
231 		device_printf(dev, "HPET never increments, disabling\n");
232 		hpet_disable(sc);
233 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
234 		return (ENXIO);
235 	}
236 
237 	hpet_timecounter.tc_frequency = freq;
238 	hpet_timecounter.tc_priv = sc;
239 	tc_init(&hpet_timecounter);
240 
241 	return (0);
242 }
243 
244 static int
245 acpi_hpet_detach(device_t dev)
246 {
247 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
248 
249 	/* XXX Without a tc_remove() function, we can't detach. */
250 	return (EBUSY);
251 }
252 
253 static int
254 acpi_hpet_suspend(device_t dev)
255 {
256 	struct acpi_hpet_softc *sc;
257 
258 	/*
259 	 * Disable the timer during suspend.  The timer will not lose
260 	 * its state in S1 or S2, but we are required to disable
261 	 * it.
262 	 */
263 	sc = device_get_softc(dev);
264 	hpet_disable(sc);
265 
266 	return (0);
267 }
268 
269 static int
270 acpi_hpet_resume(device_t dev)
271 {
272 	struct acpi_hpet_softc *sc;
273 
274 	/* Re-enable the timer after a resume to keep the clock advancing. */
275 	sc = device_get_softc(dev);
276 	hpet_enable(sc);
277 
278 	return (0);
279 }
280 
281 /* Print some basic latency/rate information to assist in debugging. */
282 static void
283 acpi_hpet_test(struct acpi_hpet_softc *sc)
284 {
285 	int i;
286 	uint32_t u1, u2;
287 	struct bintime b0, b1, b2;
288 	struct timespec ts;
289 
290 	binuptime(&b0);
291 	binuptime(&b0);
292 	binuptime(&b1);
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);
296 	binuptime(&b2);
297 	u2 = bus_read_4(sc->mem_res, HPET_MAIN_COUNTER);
298 
299 	bintime_sub(&b2, &b1);
300 	bintime_sub(&b1, &b0);
301 	bintime_sub(&b2, &b1);
302 	bintime2timespec(&b2, &ts);
303 
304 	device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
305 	    (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
306 
307 	device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
308 }
309 
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),
318 
319 	{0, 0}
320 };
321 
322 static driver_t	acpi_hpet_driver = {
323 	"acpi_hpet",
324 	acpi_hpet_methods,
325 	sizeof(struct acpi_hpet_softc),
326 };
327 
328 
329 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
330 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);
331