gfrtc.c revision 1.6
1 /* $NetBSD: gfrtc.c,v 1.6 2025/09/07 04:46:59 thorpej 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 1.6 2025/09/07 04:46:59 thorpej 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 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 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 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 todr_attach(&sc->sc_todr); 110 } 111 } 112 113 114 void 115 gfrtc_delay(device_t dev, unsigned int usec) 116 { 117 struct gfrtc_softc *sc = device_private(dev); 118 uint64_t start_ns, end_ns, min_ns; 119 120 /* Get the start time now while we do the setup work. */ 121 start_ns = gfrtc_get_time(sc); 122 123 /* Delay for this many nsec. */ 124 min_ns = (uint64_t)usec * 1000; 125 126 do { 127 end_ns = gfrtc_get_time(sc); 128 } while ((end_ns - start_ns) < min_ns); 129 } 130 131 132 uint64_t 133 gfrtc_get_time(struct gfrtc_softc * const sc) 134 { 135 const uint64_t lo = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_LOW); 136 const uint64_t hi = GOLDFISH_RTC_READ(sc, GOLDFISH_RTC_TIME_HIGH); 137 138 return (hi << 32) | lo; 139 } 140 141 142 void 143 gfrtc_set_alarm(struct gfrtc_softc * const sc, const uint64_t next) 144 { 145 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_HIGH, (uint32_t)(next >> 32)); 146 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_LOW, (uint32_t)next); 147 } 148 149 150 void 151 gfrtc_clear_alarm(struct gfrtc_softc * const sc) 152 { 153 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_ALARM, 0); 154 } 155 156 157 void 158 gfrtc_enable_interrupt(struct gfrtc_softc * const sc) 159 { 160 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 1); 161 } 162 163 164 void 165 gfrtc_disable_interrupt(struct gfrtc_softc * const sc) 166 { 167 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 0); 168 } 169 170 171 void 172 gfrtc_clear_interrupt(struct gfrtc_softc * const sc) 173 { 174 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_INTERRUPT, 0); 175 } 176
Indexes created Mon Oct 13 16:09:52 GMT 2025