gfrtc.c revision 1.3
1/* $NetBSD: gfrtc.c,v 1.3 2024/01/02 07:26:17 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 1.3 2024/01/02 07:26:17 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 63static int 64gfrtc_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) / 1000; // Always 0? 71 72 return 0; 73} 74 75static int 76gfrtc_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 91void 92gfrtc_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 115void 116gfrtc_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 133uint64_t 134gfrtc_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 143void 144gfrtc_set_alarm(struct gfrtc_softc * const sc, const uint64_t nsec) 145{ 146 uint64_t next = gfrtc_get_time(sc) + nsec; 147 148 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_HIGH, (uint32_t)(next >> 32)); 149 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_ALARM_LOW, (uint32_t)next); 150} 151 152 153void 154gfrtc_clear_alarm(struct gfrtc_softc * const sc) 155{ 156 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_ALARM, 0); 157} 158 159 160void 161gfrtc_enable_interrupt(struct gfrtc_softc * const sc) 162{ 163 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 1); 164} 165 166 167void 168gfrtc_disable_interrupt(struct gfrtc_softc * const sc) 169{ 170 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_IRQ_ENABLED, 0); 171} 172 173 174void 175gfrtc_clear_interrupt(struct gfrtc_softc * const sc) 176{ 177 GOLDFISH_RTC_WRITE(sc, GOLDFISH_RTC_CLEAR_INTERRUPT, 0); 178} 179