1 /* $NetBSD: gfrtc.c,v 1.5 2024/03/05 11:19:30 isaki Exp $ */
2
3 /*-
4 * Copyright (c) 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nick Hudson and by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: gfrtc.c,v 1.5 2024/03/05 11:19:30 isaki Exp $");
34
35 #include <sys/param.h>
36
37 #include <sys/bus.h>
38 #include <sys/device.h>
39
40 #include <dev/goldfish/gfrtcvar.h>
41
42 #define GOLDFISH_RTC_TIME_LOW 0x00
43 #define GOLDFISH_RTC_TIME_HIGH 0x04
44 #define GOLDFISH_RTC_ALARM_LOW 0x08
45 #define GOLDFISH_RTC_ALARM_HIGH 0x0c
46 #define GOLDFISH_RTC_IRQ_ENABLED 0x10
47 #define GOLDFISH_RTC_CLEAR_ALARM 0x14
48 #define GOLDFISH_RTC_ALARM_STATUS 0x18
49 #define GOLDFISH_RTC_CLEAR_INTERRUPT 0x1c
50
51 /*
52 * https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
53 *
54 * (Despite what the Google docs say, the Qemu goldfish-rtc implements
55 * the timer functionality.)
56 */
57
58 #define GOLDFISH_RTC_READ(sc, reg) \
59 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
60 #define GOLDFISH_RTC_WRITE(sc, reg, val) \
61 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
62
63 static int
gfrtc_gettime(struct todr_chip_handle * ch,struct timeval * tv)64 gfrtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
65 {
66 struct gfrtc_softc *sc = ch->cookie;
67 const uint64_t nsec = gfrtc_get_time(sc);
68
69 tv->tv_sec = nsec / 1000000000;
70 tv->tv_usec = (nsec - tv->tv_sec * 1000000000) / 1000;
71
72 return 0;
73 }
74
75 static int
gfrtc_settime(struct todr_chip_handle * ch,struct timeval * tv)76 gfrtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
77 {
78 struct gfrtc_softc *sc = ch->cookie;
79
80 const uint64_t nsec = (tv->tv_sec * 1000000 + tv->tv_usec) * 1000;
81 const uint32_t hi = (uint32_t)(nsec >> 32);
82 const uint32_t lo = (uint32_t)nsec;
83
84 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_HIGH, hi);
85 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_TIME_LOW, lo);
86
87 return 0;
88 }
89
90
91 void
gfrtc_attach(struct gfrtc_softc * const sc,bool todr)92 gfrtc_attach(struct gfrtc_softc * const sc, bool todr)
93 {
94
95 aprint_naive("\n");
96 aprint_normal(": Google Goldfish RTC + timer\n");
97
98 /* Cancel any alarms, make sure interrupt is disabled. */
99 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 0);
100 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_ALARM, 0);
101 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_INTERRUPT, 0);
102
103 if (todr) {
104 aprint_normal_dev(sc->sc_dev,
105 "using as Time of Day Register.\n");
106 sc->sc_todr.cookie = sc;
107 sc->sc_todr.todr_gettime = gfrtc_gettime;
108 sc->sc_todr.todr_settime = gfrtc_settime;
109 sc->sc_todr.todr_setwen = NULL;
110 todr_attach(&sc->sc_todr);
111 }
112 }
113
114
115 void
gfrtc_delay(device_t dev,unsigned int usec)116 gfrtc_delay(device_t dev, unsigned int usec)
117 {
118 struct gfrtc_softc *sc = device_private(dev);
119 uint64_t start_ns, end_ns, min_ns;
120
121 /* Get the start time now while we do the setup work. */
122 start_ns = gfrtc_get_time(sc);
123
124 /* Delay for this many nsec. */
125 min_ns = (uint64_t)usec * 1000;
126
127 do {
128 end_ns = gfrtc_get_time(sc);
129 } while ((end_ns - start_ns) < min_ns);
130 }
131
132
133 uint64_t
gfrtc_get_time(struct gfrtc_softc * const sc)134 gfrtc_get_time(struct gfrtc_softc * const sc)
135 {
136 const uint64_t lo = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_LOW);
137 const uint64_t hi = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_HIGH);
138
139 return (hi << 32) | lo;
140 }
141
142
143 void
gfrtc_set_alarm(struct gfrtc_softc * const sc,const uint64_t next)144 gfrtc_set_alarm(struct gfrtc_softc * const sc, const uint64_t next)
145 {
146 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_HIGH, (uint32_t)(next >> 32));
147 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_LOW, (uint32_t)next);
148 }
149
150
151 void
gfrtc_clear_alarm(struct gfrtc_softc * const sc)152 gfrtc_clear_alarm(struct gfrtc_softc * const sc)
153 {
154 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_ALARM, 0);
155 }
156
157
158 void
gfrtc_enable_interrupt(struct gfrtc_softc * const sc)159 gfrtc_enable_interrupt(struct gfrtc_softc * const sc)
160 {
161 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 1);
162 }
163
164
165 void
gfrtc_disable_interrupt(struct gfrtc_softc * const sc)166 gfrtc_disable_interrupt(struct gfrtc_softc * const sc)
167 {
168 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 0);
169 }
170
171
172 void
gfrtc_clear_interrupt(struct gfrtc_softc * const sc)173 gfrtc_clear_interrupt(struct gfrtc_softc * const sc)
174 {
175 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_INTERRUPT, 0);
176 }
177