xref: /freebsd/sys/dev/acpica/acpi_hpet.c (revision 2b743a9e9ddc6736208dc8ca1ce06ce64ad20a19)
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 
42 ACPI_SERIAL_DECL(hpet, "ACPI HPET support");
43 
44 /* ACPI CA debugging */
45 #define _COMPONENT	ACPI_TIMER
46 ACPI_MODULE_NAME("HPET")
47 
48 struct acpi_hpet_softc {
49 	device_t		dev;
50 	struct resource		*mem_res;
51 	ACPI_HANDLE		handle;
52 };
53 
54 static u_int hpet_get_timecount(struct timecounter *tc);
55 static void acpi_hpet_test(struct acpi_hpet_softc *sc);
56 
57 static char *hpet_ids[] = { "PNP0103", NULL };
58 
59 #define HPET_MEM_WIDTH		0x400	/* Expected memory region size */
60 #define HPET_OFFSET_INFO	0	/* Location of info in region */
61 #define HPET_OFFSET_PERIOD	4	/* Location of period (1/hz) */
62 #define HPET_OFFSET_ENABLE	0x10	/* Location of enable word */
63 #define HPET_OFFSET_VALUE	0xf0	/* Location of actual timer value */
64 
65 struct timecounter hpet_timecounter = {
66 	.tc_get_timecount =	hpet_get_timecount,
67 	.tc_counter_mask =	~0u,
68 	.tc_name =		"HPET",
69 	.tc_quality =		2000,
70 };
71 
72 static u_int
73 hpet_get_timecount(struct timecounter *tc)
74 {
75 	struct acpi_hpet_softc *sc;
76 
77 	sc = tc->tc_priv;
78 	return (bus_read_4(sc->mem_res, HPET_OFFSET_VALUE));
79 }
80 
81 static int
82 acpi_hpet_probe(device_t dev)
83 {
84 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
85 
86 	if (acpi_disabled("hpet") ||
87 	    ACPI_ID_PROBE(device_get_parent(dev), dev, hpet_ids) == NULL ||
88 	    device_get_unit(dev) != 0)
89 		return (ENXIO);
90 
91 	device_set_desc(dev, "High Precision Event Timer");
92 	return (0);
93 }
94 
95 static int
96 acpi_hpet_attach(device_t dev)
97 {
98 	struct acpi_hpet_softc *sc;
99 	int rid;
100 	uint32_t val;
101 	uintmax_t freq;
102 
103 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
104 
105 	sc = device_get_softc(dev);
106 	sc->dev = dev;
107 	sc->handle = acpi_get_handle(dev);
108 
109 	rid = 0;
110 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
111 	    RF_ACTIVE);
112 	if (sc->mem_res == NULL)
113 		return (ENOMEM);
114 
115 	/* Validate that we can access the whole region. */
116 	if (rman_get_size(sc->mem_res) < HPET_MEM_WIDTH) {
117 		device_printf(dev, "memory region width %ld too small\n",
118 		    rman_get_size(sc->mem_res));
119 		bus_free_resource(dev, SYS_RES_MEMORY, sc->mem_res);
120 		return (ENXIO);
121 	}
122 
123 	/* Read basic statistics about the timer. */
124 	val = bus_read_4(sc->mem_res, HPET_OFFSET_PERIOD);
125 	freq = (1000000000000000LL + val / 2) / val;
126 	if (bootverbose) {
127 		val = bus_read_4(sc->mem_res, HPET_OFFSET_INFO);
128 		device_printf(dev,
129 		    "vend: 0x%x rev: 0x%x num: %d hz: %jd opts:%s%s\n",
130 		    val >> 16, val & 0xff, (val >> 18) & 0xf, freq,
131 		    ((val >> 15) & 1) ? " leg_route" : "",
132 		    ((val >> 13) & 1) ? " count_size" : "");
133 	}
134 
135 	/* Be sure it is enabled. */
136 	bus_write_4(sc->mem_res, HPET_OFFSET_ENABLE, 1);
137 
138 	if (testenv("debug.acpi.hpet_test"))
139 		acpi_hpet_test(sc);
140 
141 	hpet_timecounter.tc_frequency = freq;
142 	hpet_timecounter.tc_priv = sc;
143 	tc_init(&hpet_timecounter);
144 
145 	return (0);
146 }
147 
148 static int
149 acpi_hpet_detach(device_t dev)
150 {
151 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
152 
153 	/* XXX Without a tc_remove() function, we can't detach. */
154 	return (EBUSY);
155 }
156 
157 /* Print some basic latency/rate information to assist in debugging. */
158 static void
159 acpi_hpet_test(struct acpi_hpet_softc *sc)
160 {
161 	int i;
162 	uint32_t u1, u2;
163 	struct bintime b0, b1, b2;
164 	struct timespec ts;
165 
166 	binuptime(&b0);
167 	binuptime(&b0);
168 	binuptime(&b1);
169 	u1 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
170 	for (i = 1; i < 1000; i++)
171 		u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
172 	binuptime(&b2);
173 	u2 = bus_read_4(sc->mem_res, HPET_OFFSET_VALUE);
174 
175 	bintime_sub(&b2, &b1);
176 	bintime_sub(&b1, &b0);
177 	bintime_sub(&b2, &b1);
178 	bintime2timespec(&b2, &ts);
179 
180 	device_printf(sc->dev, "%ld.%09ld: %u ... %u = %u\n",
181 	    (long)ts.tv_sec, ts.tv_nsec, u1, u2, u2 - u1);
182 
183 	device_printf(sc->dev, "time per call: %ld ns\n", ts.tv_nsec / 1000);
184 }
185 
186 static device_method_t acpi_hpet_methods[] = {
187 	/* Device interface */
188 	DEVMETHOD(device_probe, acpi_hpet_probe),
189 	DEVMETHOD(device_attach, acpi_hpet_attach),
190 	DEVMETHOD(device_detach, acpi_hpet_detach),
191 
192 	{0, 0}
193 };
194 
195 static driver_t	acpi_hpet_driver = {
196 	"acpi_hpet",
197 	acpi_hpet_methods,
198 	sizeof(struct acpi_hpet_softc),
199 };
200 
201 static devclass_t acpi_hpet_devclass;
202 
203 DRIVER_MODULE(acpi_hpet, acpi, acpi_hpet_driver, acpi_hpet_devclass, 0, 0);
204 MODULE_DEPEND(acpi_hpet, acpi, 1, 1, 1);
205